What killer-duck is saying is correct, though it could also be a hammer glitch: Hammer, unbelievably, sometimes compiles a different map than you specify. This can be a very confusing/annoying glitch to say the least. (the reason I stopped using Hammer to compile my maps)
You could try renaming the map to fix the aformentioned glitch, or, for a much better solution: DO NOT USE HAMMER TO COMPILE.
I just compiled a diary/log of errors and mapping problems, and at least 1/3 of the trouble was directly caused by hammer compile process and Hammer-related glitches.
Seriously, do yourself a big favor, get batch compiler now!
Download!We'd be happy to help you set i up if you need. = )