Can't export or share my projects

I have about 20 high school soccer games plus a couple hours extra footage, edited down to a 145 minute project. But now I can't share or export - the choices are all greyed out. I've narrowed down the problem to a couple games that I must have imported differently. According to the info, the bad footage is "File Type: AVCHD plugin". All the rest of my footage is "File Type: quicktime movie." I've tried to reimport the clips, and nothing seems to change. I tried relink project files, but no options come up. I tried transcoding the media, and get the following message:

Camera Clips Selected

Camera clips cannot be processed. You must import/reimport these first in order to process.

Just about all of the footage was captured by me copying the footage directly from my SD card to my hard drive, then "Import media from a connected device." I'm beginning to think I'm doing this incorrectly because FCPX thinks I have 20+ cameras connected to the computer, but these are the only two games I've had any problems with.

One more thing, there's an icon by my Event and each of my Projects that looks like a yellow triangle with a '!' inside.

And then every time I repoen my main project, it has to rerender all of my titles. I think all of these problems are related...

BTW I'm running FCPX 10.0.4 on a 2.2 GHz Intel Core i7 PowerBook laptop with 8GB RAM, running Mac OS 10.7.4, with an external 2 TB hard drive containing all of my footage. I've transcoded all my media to be using proxy media because I felt the computer was lagging a little. This is my first project with FCPX, so I've been learning as I go...

Thanks!