Problem upgrading from 1.1.4 to 2.0 beta 3p

[Etinin]

When I try to upgrade my forum (an altered copy of the live one), the upgrade stalls with this message (even though I enabled debugging in the beginning):

Executing upgrade script 1 of 2.
Executing: "Updating and creating indexes..." (1 of 19 - of this script).

Database Updates Complete! Click Continue to Proceed.
Updating indexes on "messages"...
!!
Error!

I have tried it several times without success and if I copy the original 1.1.4 files over the upgraded ones, the forum works normally. I have also removed all custom themes and mods to rule out problems caused by them. Any idea on what could've gone wrong or on what I could do to generate further debugging information?

Link to forum: hxxp:hardbrasil.org/NewSMF/ [nonactive] (now offline)

Thanks for any help.

[Etinin]

Nobody has any idea?

[metallica48423]

have you tried running repair and optimize on the database via phpmyadmin prior to upgrading?

Anything in the apache error log?

Unfortunately, without a solid error message theres little we can guess to deduce what is causing the error other than guesswork