I just released some code last saturday. What I didn't notice, was the TortoiseSVN inserted a localized date into the source code in a $LastChangedDate:$ text, even though I deliverately use it with English user interface.
In Danish, there are non-ascii characters in the weekday names for saturday (lørdag) and sunday (søndag), so this made the source code file become a non-ascii file, which basically broke it for some users. Today I rereleased the files, and because it's monday (mandag), the problem is gone :-)
I guess that was another lesson on how not to localize.