sur certain serveur le p_xxx.mdl il considere comme des cheats alors faut pas les installer ...
Problems with this skin?
Please first make sure that you have it installed properly. Check for spelling mistakes, and spaces.
If the problem you encounter looks something like this:
enforcing file consistency for file half-life/cstrike/models/p_weapon.mdl
A file consistency check was put in to prevent 'spiked-models' used by cheaters. As a result, some weapon models that were not made to cheat, are now too large. Both the v_x.mdl and w_x.mdl models are not affected by this check.
To fix the error, simply replace the invalid file with the default p_x.mdl model, you only need to replace the p_x.mdl. The defaults are available here.
If you encounter this error with a player model, trash it and let me know the name and what category it is in.
(source : http://www.cs-skins.net/ )