S!
Same problem for me, I've tried to change variuos graphic options without results.
Then I've remembered a similar problem with Battlefield 2 demo solved after a long research on Internet, it was caused by the refresh rate fixing software. So I've tried this tip... and now T-72 work!
Here you can find the tip:
http://homepage.ntlworld.com/gamezone/help/scr-prob.htm
I hope this helps you.