disk fragmentation and Protools, I can't record because of hard drive? Options

My mac powerbook G3 suddenly won't let me record in protools. When I put it in record mode and press play it says ' can't perform that function. Disk may be fragmented.'

I have about 900 MB of hard drive space left; I know I need more, but I had been using protools for a while with less.

I opened a new session to try again, and it let me record if I used the crappy built in mic (just snapping my fingers near mic hole.) But it didn't work if I used the sound input port like usual. It gave the same message. When I closed the session-- not having saved any audio at all-- the file took up over 800 MB, with nothing recorded. I threw it away and got my hard drive space back, but I really need to use protools this weekend. Any suggestions? (especially if there was some cheap and fast solution)

Thank you,
jess

I'm not at home to see exactly where it is, but in the preferences there's a disk or time allocation setting and yours set to 'unlimited' or 'open ended' or something like that. If you'll specify a time (like 6 minutes) your problem will go away. Pro Tools will see plenty of 6 minute blank chunks on your hard drive and let you cut your parts.