Remembering that I thought it was pretty decent, I went looking in SONAR X3 Producer for the Cakewalk Studio Instruments bass guitar softsynth (if I remember it came with X2 Producer) and it's not there. Does X3 not support these?

Looked like it was present in my synth list in my version of X3.
I will go down in the morning and make sure. I always liked those studio instruments.
WSS

 Check this out. All versions of X3 come with it

Even if it had been removed from X3 (it wasn't) it should still be there from your X2 install. First, take a look and make sure it really is still there. SI samples are in their own folders under Studio Instruments, under the Cakewalk folder, and the dlls are under vstplugins. Assuming everything's there try running a plugin scan, then check the inventory and make sure it's listed under "VST Instruments".

Plug in scan was the first thing I tried. I also looked in the Vstplugins folders. No trace of the DLLs anywhere. There are track templates are in C:\Cakewalk Content\SONAR X3 Producer\Track Templates\Soft Synth Track Templates. The bitmaps used in the UI are in C:\Cakewalk Content\SONAR X3 Producer\Track Icons\Soft Synths. But no DLLs in the typical locations.
 
 

Have you manually moved files on your computer? If you do a custom installation of X3, you can skip the program files and re-install all of the soft synths, etc. via that method.

mettelus, no, didn't manually move anything related to that. I was thinking about trying the installer and seeing if it had those options - used to be a fairly standard thing for application installers to do in case you wanted to add stuff later that you chose not to at the initial installation. I'll do that, that should take care of it.

I would do a manual re install of sonar x3 (only those plug ins.)
I would even use x2 and not x3 to be honest, don't ask.
if the plugs are there, remove any remanence first, then custom install by installing those ONLY

In X3, open the Browser, then under the Instuments tab (next to the Rewire tab), there are two listings.. a VST2 and DirectX.  Open the vst2 folder and they are listed as SI Bass Guitar,  etc  4 in all.  I hope this helps.

Thanks, FCCfirstclass, but that's how I know they are not there - they are not in that list.