During a custom-class installation, I got an error which gave the
message, "An exceptional condition has occured [sic]. This is most
likely a bug. Please copy the full text...."

I'm a newbie and would welcome any help you can give me figuring
this out. If you could reach me by the end of the day I'd be
exceptionally grateful, so I can continue installing and using
Linux over the weekend.

The text is as follows:

Traceback (innermost last):
File "/var/tmp/anaconda-7.0.1//usr/lib/anaconda/iw/progress_gui.py",line 
20, in run
rc=self.todo.doInstall()
File "/var/tmp/anaconda-7.0.1//usr/lib/anaconda/fstab.py", line 713, in 
mountFilesystems
raise SystemError, (errno, msg)
SystemError:(22, 'Invalid argument')