Saw this upstairs: http://forum.cakewalk.com/SONAR-X3-and-UAD-plugins-A-FIX-FINALLY-m2992140.aspx
 

Hmmmm...OK, I'll try it.

Wow, just gone to download - its says the download is 1.2gig!!
This seem massive - the usual updates iirc were about 150mb

Actually, I thought it seemed pretty large, but I have the last few in a folder and they have gradually gotten bigger with each release. Last one was almost a gig.
 
Now the trick is to find time to play around with it.  Having a real job and going to school really eats into my fun time.

 The new driver was a disaster here on my UAD-2 solo card. The driver loads up as far as the device manager is concerned, but the control panel gives an error on loading and all UAD plugs no longer working at all on my win 7 partition.
 I tried to reinstall the old driver and for some reason now all older UAD installers will not install the plugs, just the driver.
 Last straw with UAD here, I will use a few mastering plugs at some point in my XP partition, but for the most part I'm using alternatives.
 

The v7.5 update working great here with all of my UAD devices connected together (UAD-2 QUAD PCIe, UAD-2 SOLO PCIe and Apollo QUAD). The two issues (UAD warning message when placing a native between UAD and inactive UAD plug-ins in the pro channel FX bin)  have been resolved. 
 
FYI: ohgrant, using XP?.............while XP should work.........the minimum recommended, tested and supported OS for v7.5 is Win7 x64 (SP1). In fact, I think that Win 7 (SP1) x64 has been the minimum supported OS since the official x64 plug-ins release way back @ v6.4. Maybe, that has been part of your issue. Seriously, if I were you, I would do one of two things...either upgrade to Win 7 x64 (SP1) and stay current or stay with XP and use v6.3.1 or earlier. Of course, to get current bug fixes and plug-in updates you really need to be on Win 7 x64 (SP1). Since UAD v6.4, UA has focused plug-in & platform development and it's bench testing on 64bit OS platforms (both Win/Mac). 
 
Cheers,
 
Billy Buck

Did you do a complete uninstall prior to installing the new driver?  I've been doing that with each new release of UAD plugins (ever since someone in a thread on here suggested it.)  It's one of a couple of "undocumented workarounds" that UAD plugins seem to need in order to function with SONAR.  The other is to make sure only the 64bit plugins are in your VST scan path if you are using SONAR x64.

Genghis
Did you do a complete uninstall prior to installing the new driver?  I've been doing that with each new release of UAD plugins (ever since someone in a thread on here suggested it.)  It's one of a couple of "undocumented workarounds" that UAD plugins seem to need in order to function with SONAR.  The other is to make sure only the 64bit plugins are in your VST scan path if you are using SONAR x64.

You should never have to do a complete un-install of the UAD system when updating. If that is the case, then there is something else going on in your computer that is corrupting the UAD install. I have been a longtime SONAR user (every release since version 1.0 in 2001) and I have been using UAD cards with SONAR since 2002. I have literally installed every single UAD update since then (well over 50 if you are counting) and I have always done a simple "over the top" (which UA recommends ) update every time. One of the reasons for this, if you completely un-install all of the UAD software components then a new update is treated as a new install. Which means you may need to power down, take the PCIe card out, re-boot computer, install UAD software, power down and install card, re-boot and follow the final UAD install prompts (if any). Installing a UAD card any other way  (always software first/ power down and install card)......can lead to performance issues down the line.
 
Cheers,
 
Billy Buck

ohgrant
 The new driver was a disaster here on my UAD-2 solo card. The driver loads up as far as the device manager is concerned, but the control panel gives an error on loading and all UAD plugs no longer working at all on my win 7 partition.

 
I see you are actually using Win7 (SP1) on another partition. Are you using that as your "C" drive when you open in the Win7 OS? The UAD software (especially since v6.4) is very particular as to where it gets installed and it will automatically (there is no way to change it) install to the "C" drive. From the look of it, it appears you may have a corrupt install of the UAD software. I would recommend un-installing the UAD software & all traces of UAD drivers (very important) from your "C" drive and take the card out of the PCIe slot. There are detailed procedures for doing so on the UAD support pages. Then I would do a fresh install of version 7.5 (as if installing for the first time). Install UAD software, power down, install UAD card, re-boot and follow the install prompts. You may need to re-boot again to complete the install. Once complete, any further updates can be made "over the top".
 
Best of luck,
 
Billy Buck
 

Hmmm... interesting thoughts Billy Buck. I've never had any serious issues, but started doing that when I think Danny Danzi suggested it for some others with more serious issues.  I'll keep that in mind. 
 
The only real problems I have ever had has come from both the 64 and 32 bit plugins being in the scan path. Also the display meters have occasionally stopped responding on a the LA-2A plugins a time or two.