Having trouble "roundtripping" between FCP 6 and Soundtrack Pro 2

I've been a FCP user since it first came out, and believe it or not, this is my first attempt at roundtripping with Soundtrack Pro. Basically the process goes pretty good until it's time to go back to FCP.

Here's my workflow: In FCP I highlight the audio clip in the timeline. I select Send To > Soundtrack Pro Audio File Project. It creates a (sent) file, which I save (Save project with latest clip metadata is selected). Once the clip opens in Soundtrack Pro, I make the adjustments I need to make (in this case, I'm getting rid of some background noise), then I save (Include Source Audio is selected).

Here's where the problem comes in. When I go back to FCP, I get the "Some files went offline" warning. When I try to reconnect, I get the following warning:

"File Attribute Mismatch

Some attributes of one or more of the files you have chosen do not match the attributes of the original. This may cause problems within the sequences that are dependent on them. The attributes that differed are as follows:

- Media Start and End

Would you like to try to connect them again?"

When I go to the folder where the modified (sent).stap is saved, it opens and plays back fine. However, it looks like Soundtrack Pro is saving the full clip (from the original footage), not just the selection from my timeline. I'm assuming this is why I'm getting the "File Mismatch" error (basically it's too long).

Is there a step I'm missing? Any help would be greatly appreciated!