Thanks so much for your help! Here’s the deal–I’ve now got about 10 minutes’ worth left to render in this sequence. For some reason, the computer is letting me render in smaller sections but it still won’t let me render the whole thing at once. I’ve still got 77 gigs of scratch disk space available, and the last section i rendered was 2 minutes long and took up less than a gig. There’s one two minute section (and there may be more sections like this) that gives me the “insufficient disk space” message, but there’s nothing fancy about it in terms of filters, in fact it’s simpler than some of the other sections b/c it doesn’t have a color correction filter on it.
I already trashed my preferences and reset my scratch disk. Someone else on another forum said my hard disk permissions might be messed up, which i would repair, but i don’t have OSX installed on that disk, and you need to have it installed to repair them. Do you think i should install it?