I can't seem to use offset mode anymore after upgrading.  it used to be keyboard shortcut "o"
 
but "o" doesn't seem to do anything now.

I remember seeing a button for it on the Control Bar.

Yes, the is a button in the Mix Module. K in this image

 
"O" was removed as a default binding. It can be added back if you wish, to "Envelope/Offset Mode" in the Global Area in Preferences > Customization > Keyboard Shortcuts.

thanks guys.

I read that they removing the default key bind because so many people were enabling it by accident and not realizing that they had.

I didn't have trouble with that particular shortcut, but there are others that drive me crazy like "F" - having it resize all of my tracks when I'm working on a particular track just takes my becan!

You can edit the key bindings to your heart's content (although the interface seems a bit clunky to me, not that I have any brilliant ideas how it could be better...) if you change the mode on the Preferences popup from Basic to Advanced - selection is at bottom left of the window.

yes, but every time I upgrade sonar my keybindings and my folder preferences always seem to revert back to default.  for example, my projects folder is on drive: Z:\Cakewalk Projects
instead of the default C:\Cakewalk Projects
 
but without fail, when I upgrade it reverts back to the default and I have to change the preferences again. 
 
same for the keybindings.  I got tired of editing them after every upgrade.

and FWIW, it did ask me during install if it should keep the settings from a particular location from the last version, but it still reset those things.

You can import and export settings files manually - I don't use that much customization so I've never tried it, especially across major versions - but it's on the keyboard shortcuts page, towards the bottom right. Might be a solution - fire up X3 and make an export file if you had it set the way you wanted, try importing it to Platinum...