Map change and Anti-Aliasing

[~xS-R|Marines]

Hello all!

I recently installed Battlefield 2 (and Project Reality) in my new computer and it runs pretty good, except for two things:
1. When I'm playing Vanilla (haven't tried this in PRM), I connect to a server, play the map and when the round is over it loads a new map. After finishing the map loading (the 2nd map), it kicks me saying my BF2 content's been modified. If I reconnect, I can play normally.

2. In some guns the Anti-Aliasing causes a strange effect, some surfaces behave like if they were liquid, in the weapons. The easiest weapon to see this is the MP5, in between the receiver and the chamber.

Thanks!

P.S.:
Windows 7 Ultimate 64-bit
Intel i7 920
DX58SO Motherboard
6GB RAM
GeForce GTS250