It might be because you have the wrong
file
ETPro 3.2.6 : <a href="http://returntocastlewolfenstein.filefront.com/file/ETPro_326;69919">[Clicky]</a>
ET 2.60b Patch: <a href="http://returntocastlewolfenstein.filefront.com/file/Wolfenstein_Enemy_Territory_260b_Patch_win32;62012">[Clicky]</a>
You probably want the bottom one