I know dropout is a common topic; but I'm having a very specific issue.  My set up is an Intel i7 processor, 12 GB ram and plenty of hard drive space.  Using VS-100 as my sound device.  When I am editing sound and I have the waveform spread out to show just a few measures, if I try to use the <<  or >> controls (hardware buttons on the VS-100 or just the onscreen controls), or try to drag the now time at the top of the time ruler with the mouse to back up and listen to something in the track, I get dropout and have to restart the transport.  Increasing or decreasing latency settings in the ASIO driver doesn't seem to help.  If I'm looking at the whole song, or a large portion thereof, I can drag the now time back and forth with no dropout. It only occurs when the measures are spread out enough to actually see the measure and waveform where something is going on with the sound. 
 
Any help would be appreciated.  I apologize in advance if this is something I should know; but most of the dropout issues I am familiar with are related to the latency settings, having other things on the machine disabled, and such. 
 

Gosh, not obvious, KellyG.
 
One constraint that could get you is if you are having IO problems. This means big files. Under Preferences Audio Files ... are they set to 32 bit by any chance? They record should be set to 24 bit.
 
If you bypass all FX by hitting the E key on your keyboard do you still have the dropouts?

I would suggest starting with the following settings, for recording sessions in Sonar:
 
Audio interface: Sample Rate 48 k, ASIO Buffer Size of 128
 
Sonar: Driver Mode of ASIO, Sample Rate 48 k, Record Bit-Depth of 24-bits - try to get your Total Rountrip Latency down to around 10 milliseconds or just under.
 
Once you get your settings as noted above, please test them out in a new project with no loaded effects, just to make sure all is well.
 
If you are having dropouts with those settings and no effects, then I would suggest you look at other background services that may be interfering with Sonar's operation, such as antivirus software, a Wi-Fi adapter, that sort of thing.  DPC Latency Checker or LatencyMon running for a few minutes WITHOUT Sonar running will give you an idea of your computer's basic ability to handle audio streaming, such as what Sonar does.
 
If the above testing works, and you do not have dropouts, then I would suggest that one or more plugins (effects) in whatever projects are having dropouts are not really meant to be used in the recording process, but instead are meant for mixing/mastering.  This can be tested by loading one of these projects, then hitting 'E' on your computer keyboard, which will toggle on/off Bypass All Effects.  If your dropouts go away after hitting 'E', then you need to look closely at each effect, to make sure it doesn't do 'look-ahead' processing or otherwise consume giant bunches of CPU cycles.  Things like Boost 11, Perfect Space, and LP-64 EQ all can cause massive recording latency, and should only be loaded into projects during mixing/mastering.
 
I truly hope that above helps you, 
 
Bob Bone
 

Thoughtful and detailed reply. Thank you, belatedly.

This thread is on YOUR schedule, not ours.  :)
 
Can you please give us an idea of where things stand with this issue for you?
 
Have you tried any of the settings I posted?
 
Bob Bone
 

Check for updated graphics drivers, just in case.

At the time I made the original post, I was finishing up a project in collaboration with a studio which has only Sonar 8.5 and learning X3e in my spare time. My graphics card drivers are pretty old, I am sure, because the graphics card is probably 4 years old; but I am on Microsoft update for anything they put out from their site.
I did try several of the things suggested in this post.  I am familiar with the basic settings and the DPC latency checker due to the excellent history maintained on this forum. 
 
I think I have narrowed the issue down to a track with about 20 track lanes of bass takes.  At some point, I clicked on the AudioSnap, thinking I could work on a flattened comp lane with pitch and timing corrections.  At that point Sonar got really busy with creating transient markers all over the place and I think that is where my problem started.  If I freeze that track, the transport seems to resume smoothly. If it is not frozen, I can play the song through okay but if I try to use the quick comp or loop through a section to try different lanes, it stutters and stops. I had one actual crash the other day and let the system send the dump to Cakewalk. I have tons of CPU and RAM available. I have noticed the disk load meter blinking red just before the transport stops sometimes.
 
The good news is that I am just doing this for fun right now to learn the features added since Sonar 8.5 before I start any sort of new project. The bad news is I'm behind the learning curve a little and don't always know if something is wrong with the software or the way I'm using it. The comp feature was one of the things I thought was really cool in the new version and wanted to learn; but I don't think I entirely understand it in comparison to using multiple takes to a track and editing them together the old-fashioned way. I probably inadvertently caused my own problem.
 

Yoi will need to go to the third party site to download the correct graphics drivers. Also please Google 'Intel auto update' and make sure you are on the latest firmware and drivers for your audio interface. Ta