Wow gang... thanks for all of that! Not sure why I didn't receive any notice that anyone had responded... I should have known you would, and I should have checked!
 
I can import audio or MIDI files without a problem, and I do run Sonar as Administrator so that a couple of plug-ins that I really like continue to work. I'm going to have to look into elevating privileges as suggested earlier. In the meantime I will run Sonar as me and see if that fixes things.
 
At the moment the only plug-in I can think of that requires me to run Sonar as Administrator is Pentagon, but I think I might have the same issue with Session Drummer 3. I'll check both tonight and report back.

Thanks again all!

Check:
http://forum.cakewalk.com/FindPost/1966631
 
I don't think Session drummer will be effected.
 
Thanks..

Thanks to all! It was a privileges issue, I was running Sonar as admin, and that was preventing drag and drop from working properly.
 
Thus far all plug-ins, except Pentagon, seem to be working properly. At least all the plugins I use regularly are working properly, saving presets, etc.

I'm about to give that registry edit (link above) a shot to see if that resolves the Pentagon problem.

And then I think I'll just reinstall Session Drummer - not sure what happened there.

Thanks again!

And the registry edit restored Pentagon.
 
I'm down to one or two minor issues now, and then I'll finally have my new DAW where my old DAW was in terms of workflow.
 
All things considered, the "upgrade" from Win7 to Win8 has proven to be relatively painless. Not as smooth as the upgrade from XP to Win7, but certainly a lot smoother than other upgrades I remember.

Thanks again for the tips about running as admin and the registry edit.