Ah! <slaps forehead> Sorry, I was definitely confused and misunderstood what you were saying. I thought you were pointing out a side effect of fixing the feat selection at level 13. Thanks for clearing that up.
Should this fix work on an existing game or not? I'm running Co8 5.0.0 with the 03-AUG-2006 cumulative patches. I had a level 12 rogue with enough experience to level up to 13 before I applied this fix (renamed old temple.dll and copied contents of .RAR into ToEE root). Levelling up the rogue does not allow for rogue feat selection (all feats are shown in white and none can be selected). Hopefully, this is just because it was an existing game or circumstances (or I did something wrong).
RTFM. (or RTFP) I tried it again after replacing the correct temple.dll. Indeed I am able to select a feat at level 13, but, in addition to the rogue feats, I can also pick pretty much any standard feat that doesn't require a secondary specification (e.g., not available are weapon focus, improved critical, skill focus, and exotic weapon proficiency -- they show up in white (not yellow)).
This is in accordance with the rules. Rogues can choose to take a feat instead of a special ability. http://www.d20srd.org/srd/classes/rogue.htm