As a fellow Roland Quad Capture user, I can tell you that at least part of the problem lies with the interface or the drivers, themselves.  Check the forum, and you'll find countless posts referencing Roland interfaces.
 
With that said, most of the times when I have trouble with dropouts, ect, it usually has to do with changes recently made by the operating system, either through updates, or other system changes.  Here are a few things that I check first, when random dropouts start happening.
 
1.  Power Options - I've gone through and created a customized power profile for my system which gives me the best settings for music production.  Frequently I find that the operating system has, for some reason, switched back to Windows 10's, generic "Balanced" power profile, which is not optimal for music production.   In Windows 10, click the Start Button, go to "Settings" then "System", then "Power&Sleep".  On that screen you can select a power profile for your system, or go to advanced settings and create a custom profile.
 
2.  USB Power Management - Windows loves to turn things on and off, to conserve power, this can affect performance.  To avoid this, I make sure to disable "Power Management" on all my USB devices.  This especially drives me crazy with my USB Midi Controller.  When the system puts it to sleep, I get the dreaded Midi Device Disconnected message in Sonar.  To avoid this, got to Device Manager, and find "Universal Serial Bus Controller" in the list.  Double click to open it and then double click each device inside, one at a time.  Any that have a "Power Management" tab, go to the tab and make sure to remove the check mark from "Allow The Computer To Turn Off This Device".  No more losing USB devices while working.
 
3.  This one really drives me crazy.  My laptop, as most, has an on board audio card.  Using this at the same time as an external audio card, can cause problems.  To avoid this, I go into Device Manager, under "Sound Video And Game Controllers, and disable anything related to the on board audio.  Also in device manager, go to "System Devices" and Disable anything related to your laptops on board audio.   The problem comes when windows does and update.  Often, it will turn all of this junk on again, so I check it often.  At least after every windows update.
 
I'm sure I'll think of something else, but these are the main things that I check antime dropouts start happening.

Thanks!

If all your doing with this laptop is recording a live band,?
I use an old Sony laptop that came with Vista, I upgraded to W7 64 bit, put in a 256 SSD and it has the max 4 Gigs RAM. So this is no killer machine by any stretch. But It has been optimized for recording and has a wonderfull little WiFI switch.  
I recorded 14 tracks + midi all night long and each is a whole set worth so about 50 minutes x 4 sets.  None stop. I've been doing this since last fall. I started out with X3 on the laptop but upgraded through Pro to Plat. I too then transfer the CWP to my main DAw to work over.
 
Laptops are hit or miss I've been told. My son had a Dell that behaved like yours and there was nothing he could do. It was a $1,500 model he bought just to record. He's very tech savy. In the end it was something in the BIOS that could not be disabled that kept interupting. LAt Monitor did not show this,, he figured it out some other way. So He bought a $500 Acer that worked perfectly fine and carried on.  
My WIfes Lenovoworked excellent right out of the box and with no tweeking at all ( was not allowed too) but many others have had bad luck with almost the same laptop..

Yeah, I have a feeling that this Toshiba is a P.O.S.  I'm planning to get a new one, but not for a while.

Quick question to the OP - if you toggle on the Bypass All Effects (hit the letter 'E' on your computer keyboard to do so), do your dropouts go away?  (you can hit 'E' again to toggle the effects processing back on, afterwards, by the way).
 
IF your dropouts go away with all effects bypassed, then it indicates that one or more of the project's loaded plugins are causing your dropouts.  This is often due to things that use Linear Phase processing, or Look-Ahead processing, or are just CPU-consuming.  I noticed you mentioned Breverb - and I believe this is one of the frequent culprits for folks that add it to their projects while still recording, when it is better suited to use during the mixing phase.  Perfect Space and the LP-64 plugins are other frequent culprits.
 
Anyways - it is SUPER quick to try temporarily bypassing the effects and seeing if that helps or not.  If it does nothing to help, then the loaded plugins are not the cause.  If on the other hand, it DOES make a difference, then you need to go back and figure out which plugin(s) are contributing to your dropouts.
 
Additionally, as noted by others above, WiFi adapters, and sometimes battery management drivers can really spike DPC Latency, and cause streaming audio problems.  Many folks indeed turn off or disable both just prior to launching a Sonar session, and then turn them back on after finishing the Sonar session.
 
These issues you are reporting are NOT happening to the vast majority of users, or you would see clear evidence of that by all kinds of complaint threads.  That this is NOT the case indicates that indeed these issues are likely system-specific, and therefore likely solvable, IF one willingly engages in the process of causative analysis to figure out what alterations need to be made.
 
Bob Bone

Thanks Bob, that is good info.  I didn't know you could toggle the effects like that.  There are so many things I don't know when it comes to Sonar it's pretty sad.

Just reading through this, a bell rang in my head, and I went back to your first post. Toshiba external drive.
 
When I upgraded to X3 a few years back now, I bought a new laptop and external drive, only to find out that the Toshiba drive I bought was useless for recording, because like a laptop, it has mega power saving attributes. In other words, it shuts down. I put it to good use plugging it into the tv for recording shows, and bought a powered Seagate drive which fixed weeks of frustration after making every conceivable change to my laptop and interface settings.
 
Bob will get you going if stick with him, but keep this one in mind too.

Besides trying to record with live plugins, one other thing that may be causing dropouts on Plat but not X3 is running Platinum using the same exact settings as X3. I have found it is better to let Sonar create a new AUD.INI for each new version.
 
Regards,
Dan

My problem has been resolved.  Main things I did was to disable the wireless adapter and disable the Windows sounds.  I also refrained from using any plugins at all.  I successfully recorded 21 takes of 8 tracks of drums yesterday.  I got the dropout once, which stopped the program.  I looked at the settings and the playback/record buffer was at 256.  I thought I had already set it to 512, but maybe when I started this new project it defaulted to 256.  Whatever;  I set it to 512 and it never happened again.
 
Thanks again everyone for all your help and suggestions.  You've gone above and beyond.
 

For whatever the worth, I record with an ASIO Buffer Size of 128, to keep latency down.  I mix with it set to either 1024 or 2048 - to be able to load up the plugins during mixing.
 
Bob Bone