Game installation still failing

Hi there,
since the patch in january i havent been able to open the game. i tried deinstalling and reinstalling several times,the game continously gave the error message ''file is changed: W[2007] L[0] crossfire.exe'' - so i waited until now, waiting for a fix: i guessed after a few patches theyd fix the problem since a lot of people seem to have it.
anyway, i downloaded the game from the website and tried reinstalling; and now it says: ''your client is invalid version. reinstall the latest version game client''.

any helpful ideas?