That's weird. I don't think the DSF folder is supposed to be created since I don't have it but
things work anyway.

I just noticed another oddity. I saved a .prog file that had a reference to the phantom DSF folder to see what would happen to it.
The saved file has fixed the references to point to the folders that are on my system.

However, the file is saved with an extra .prog tagged onto the filename
so I end up with test.prog.prog. There doesn't seem to be a way to prevent this.

Maybe the X2 Studio install was thrown off by the presence of Essentials.

Why did you purchase Studio Instruments since it apparently comes with all versions of X2 ?

Sorry I can't be of more help. If I were you I'd uninstall everything,
clean the registry of traces of Sonar then install just Studio.

[This thread is also seriously messed up, format wise. It must be several feet wide...]

Yeah I don't have DSF either. I think I'm going to have to uninstall everything and start over.

I bought Essentials initially and it only came with the strings portion. I installed this from the CD.
If I am supposed to have all of them then I guess something went wrong in the install.
When I bought X2 Studio I bought Studio Instruments as well, both as a download from the Cakewalk site.
I wasn't aware that the other instruments came with X2 Studio.

Here's the comparison chartshowing what you get with the different X2 versions.

So I guess you installed things on top of each other.
I have no idea if that could cause problems.

I'd uninstall everything, then take a look in the registry to see if anything remains in the  

HKEY_CURRENT_USER/Software/Cakewalk Music Software and

HKEY_LOCAL_MACHINE/Software/Cakewalk Music Software

then reinstall just Studio.