NEED fix for iTunes error 11!

[felface]

i can't use my iPad but i am using tinyumbrella to restore my iPad and i thought i'd finally done it i've been looking for a solution for days and then iTunes said 'The iPad 'iPad' could not be restored. An unknown error occurred (11).' the thing that puzzled me though was that i did a bit of googling and it turns out that this seems to a problem mainly windows yet i'm running Mac OS X 10.7.2 on an iMac all the fixes just say 'removed bbfw file this can also be used for preserving your baseband' i can't find this find this file please could someone explain what this means or how to solve iTunes error 11?
PLEASE HELP ME!!