can't bounce selected portions of my song

[skaaat]

I've got some drum tracks that were recorded in a studio with pro tools that I'm trying to bounce to separate files right now... been trying to bounce selected portions of songs, but every time I do pro tools starts bouncing everything. I've tried reinstalling pro tools, which hasn't worked. Haven't found much help in the documentation either.

My laptop doesn't have much harddisk memory, so I've been running the files off
a usb harddrive... not sure if that's the issue, or if there's something else going on. Any help would be appreciated, thanks!