I've been on the phone with Take2 support for the past hour working on this same problem (Gigabyte Technology ATI Radeon 9550, AMD 3200+, etc) and we tried every possible solution--directx, drivers, firmware, compatibility, background programs, and so on). None of the tech guys have any idea what else to try. He has "escalated" my case, meaning it is now a top priority to be looked at by their ATI support specialist. Unfortunately it is late at night at Take2 support (are they in Australia?), so there are only 4 people in the office. He said I should hear from them first thing in the morning (their morning, whenever that may be) by email.
He said to expect a patch, barring any miracle, but the time frame he gave was 3-4 weeks. Ouch.
So far they have gotten calls from people with this problem with 3 different video cards (including my 9550). A couple people had their problem fixed by updating drivers. I was already updated, so we tried rolling back, to no avail.
I want to be mad at Take2, but the support guy was very nice and quite thorough. Unfortunately, none of his suggestions were the right one!