Permalinks broken 404

Hi,

when i have updated my blog to 3.4.1 I encountered problems with the permalink structure.

Im using /%category%/%postname%/ but it seems that the category makes problems.

I found a ticket with a patch included but i don’t know where i shall paste the code into…

the ticket is:
http://core.trac.wordpress.org/ticket/21209

thanks in advance!