Sage advise needed! Ubuntu Studio 9.10 & error 15 (in grub?)

[Henry W. Peters]

Ok, to start out with, after a "clean" install by dvd (I erased all data 
on my ext3 partition), I will, for now, only ask if someone can please 
tell me what *'error 15'* means, when loading Ubuntu Studio 9.10 (in 
'Grub,' the computer hangs & will not allow me to chose  between UBS 
9.10 or Windows XP! I had to go back to loading Ubuntu 8.01, on a live 
cd that I fortunately still had around, to get rid of that problem).

Willing to try again...

Thanks,
Henry