How to find & delete an obscure file of which I only know the name?
There are a variety of ways of searching for a file by name.  I'd just open the Terminal and run locate xxxxxxxx-xxxxxxxx, although the locate index is only updated once a week, so if it's a new file it might not be listed.  If you want, you can manually force an update with sudo /usr/libexec/locate.updatedb (you'll need to enter your admin password for the sudo).

You can use Spotlight in the Finder, but it leaves out system files by default -- there's a way to change this, but it's a little complicated and may not be the same in 10.4. (EDIT: instructions for doing this in 10.6 are in Apple's KB #HT4355.)

Finally, you could use the find command: sudo find / -name xxxxxxxx-xxxxxxxx -- this will require your admin password for the sudo, and will be slow (it actually looks at all your files to find a match), but should find things the other options might miss.