Ialso have this problem, however I do not have Steam. What I have done;
Reinstalled Arma II and Arma II RFT
Run as Admin (duh).
Ensured my AMD card drivers are up to date. I have a new AMD card so age is not an issue.
Run from directory, not shortcut
Deleted .cfg file
I have not installed any of the beta updates, and all of my troubleshooting has been done sans mods.
However I have done some testing and I can confirm, at least in my case, that it is *ONLY* the 1.62 update which is the problem. Version 1.60 works fine. The only workaround I have at the moment is to NOT install version 1.60. Hotfix anyone?