Given that this is a MacPro and therefore presumably GPT, I think this is probably the same as bug 207876, fixed upstream as follows:
2008-02-17 Robert Millan <email address hidden>
* util/i386/pc/grub-setup.c (setup): In find_first_partition_start(),
set `first_start' to 0 for non-PC/MSDOS partition maps.
Àlex Magaz, your problem can't possibly be the same as this one as the function in the original reporter's stacktrace had been entirely rewritten by well before Ubuntu 9.10. If you're still having this problem with a current version of Ubuntu, please file a fresh bug report.
Given that this is a MacPro and therefore presumably GPT, I think this is probably the same as bug 207876, fixed upstream as follows:
2008-02-17 Robert Millan <email address hidden>
* util/i386/ pc/grub- setup.c (setup): In find_first_ partition_ start() ,
set `first_start' to 0 for non-PC/MSDOS partition maps.
Àlex Magaz, your problem can't possibly be the same as this one as the function in the original reporter's stacktrace had been entirely rewritten by well before Ubuntu 9.10. If you're still having this problem with a current version of Ubuntu, please file a fresh bug report.