Source SDK - Model changing problem

[d4rkvaat1]

im having a problem with source SDK/hammer, when i make a physics multiplayer model it always appears with the hl2 models when i am trying to make a cs:s map, i have the source SDK game on cs:s, i have tried going to the [c:\steam\steamapps\email\sourcesdk\launcher\gameinfo.txt] and change the steamappid to 240 (cs:s code) but when i load source SDK it reverts my change to 240 back to 220, how can i stop it doing this or fix it another way.

thanks

-d4rk vaat1