Mapped Output Inactive.. Weird error message

[sylviesongs]

I'm working out of my laptop while I'm traveling. My playback engine is set to ProTools Aggregate, instead of my usual MOTU Ultralite. I'm running PT 9.0.5 on OSX 10.6.8. And I have a feeling that this issue started when I updated to 9.0.5 couple of days ago...

When I first open a session, I get this:

Some outputs or sends were made inactive.
Please visit the I/O Setup dialog for more information.
Some paths were made inactive because they could not be assigned to existing path definitions.

So I go to my I/O and evidently, my MainOuts are inactive. I tried deleting all the paths and clicking Default. And I was able to do it on the inputs, but on the outputs, the default button is grayed out... So then I just tried creating a new path. But it will only let me select mono (which appears inactive anyways!). When I try to select stereo, this really weird error message pops up:

Assertion in "/Volumes/Development/ws.ProTools_9.0.5/AlturaPorts/DFW/MacBuild/../Views/UMenu.MacOS.mm", line 1346

Any suggestions on how to fix this would be greatly appreciated!

Thanks in advance!
-Sylvie