I can't seem to get a straight answer on this or find a solution that works properly. Im editing a a 30i sequence and want to add 720p 29.97 footage to the timeline. Can this be done? If so, how? I feel like i've tried everything. Thanks!

try opening up a 720 project and capture all the 720 stuff.  then go into the project folder and move that bin into you 30i project folder and reopen avid

Thanks, I have done that with some sucess. It seems to work most of the time while im cutting and sometimes it gives me a decomp error. But every time I open the project I get a warning that im using "progressive footage within an interlaced timeline. This may cause you problems".

Will this warming come back to haunt me?

Cheers.

It could haunt you.

What you are doing is not supported and won't be until v3.0.

Until then, your best bet is to try and change your progressive footage into interlaced (assuming that is the least of the offtage.)  You can export from the 720p project as a QT movie then reimport into the NSTC/30i project.