So you have problems with the models, right?
Open the cstrike folder, find for config.cfg, userconfig.cfg, server.cfg, and serverconfig.cfg
Open those files with notepad, and look for "mp_consistency 1" , you must set the value to "mp_consistency 0"
If it's not there, just type mp_consistency 0 (or mp_consistency "0")
Finally save the file and play the game!
NOTE: those files MUST NOT set to read-only!