Ati Radeon HD4650 failing?

Morning, I have this issue, since I bought it, but it wasn't really a pain in the ass, I had it with Farcry2, in some parts, but now in Team Fortress 2 too. (Since the last update) and I didnt change any of my settings.
I have this problem in some games, games as Farcry2, Just Cause 2 and now TF2. But I dont get it in Call of Duty 2, 4 (MW1 and MW2) and 5, Anno 1404, Fallout 3, Guitar Hero Aerosmith and C&C 4

My TF2 settings:
http://img580.imageshack.us/img580/880/zzzzzzzzzzzzzzz....

Video of it:
http://www.youtube.com/watch?v=iOtFLcKvLr0

My specs:
Processor: Intel(R) Core(TM)2 Duo CPU E7500 @ 2.93GHz (2 CPUs), ~2.9GHz
Memory: 4096MB RAM
Hard Drive: 1 TB
Video Card: SAPPHIRE TECHNOLOGIES ATI Radeon HD 4650 ULTIMATE
Monitor: Samsumg SyncMaster 2223NW
Speakers: Logitech X-240
Mouse: Logitech USB TrackMan Wheel
Operating System: Windows 7 Ultimate 64-bit
Motherboard: Asus P5KPL-AM

Things I've done:

I ran Futuremark, and the result is: good FPS, the videocard is fine, I guess.
I checked out my heat sink, it's still okay, atleast that's what my dad said. The cooling paste is fine too. The card isnt overheated.
I ran the tool on Playtool (http://www.playtool.com/pages/memtest/memtest.html), and it didnt say anything about bad memory. That means the motherboard and main system RAM is ok.
My friend suggested enabling Vsync, but that doesnt fix the problem either.
I dont overclock my videocard.
Checked the heat sink
Checked for a good airflow
Updated my Ati Drivers
Checked if my videocard is in the right position

Thanks in advance,
Robert.