Yes, I've googled some and found a solution which crashes my Q3:
seta r_mode "-1"
seta r_customaspect "1"
seta r_customheight "1440"
seta r_customwidth "900"
seta r_fullscreen "1"
with error - 'fullscreen unavailable in this mode'

Anyone knows why? Here http://steamcommunity.com/app/2200 everyone seem to have no problems with those settings :X I've got win7 x64 btw.