The labels on the desktop are cut off at the bottom. Selecting them fixes this, but not always.
Uploading attachments is broken now: undef error - Undefined subroutine Fh::slice at /usr/lib/perl5/site_perl/5.8.8/Template/Stash.pm line 650 But I've uploaded a screenshot at http://img155.imageshack.us/img155/9486/screenshot8bq.png
Guess it's time for a Bugzilla upgrade... *sigh* Anyway, what font size and icon size are you using for the icons? I do know there are issues at some sizes, though I thought it was just very small and very large.
I have 48px icons and 8pt labels at 147 dpi. The dpi factor is probably what's killing it: someone, somewhere, assumed 96 dpi.
No, there's no dpi assumption, at least not one I can control -- though it may have something to do with it. I'll have a look at this later.
I managed to reproduce this by moving an icon with a large label from one place on the desktop to another. Should be fixed now.