Omega drivers result in system crash (Stuck with old Ati drivers)

I own Amilo Xi 1546 laptop with Ati Mobility Radeon X1800 graphics card. Since Fujitsu Siemens stopped producing graphics driver updates for that model I've been living with the same Ati driver for many months. Yesterday I decided a change was needed and had a go with Omega drivers (which had been recommended to me). I installed the latest Omega driver (based on Catalyst 7.4) properly (having uninstalled my F-S Ati driver / Catalyst Control Center beforehand). Everything went smoothly, but within a minute of playing CS: Source my system crashed. After a reboot, I tried to run 3DMARK'06. The system crashed again.

From the Omega website I remember reading that the crashed may be a result of a BIOS bug / BIOS is older. However, before intalling the Omega driver I had flashed the newest possible BIOS (1.23, made last month). I tried an older BIOS and also an older version of Omega driver, but my system kept crashing after a minute or so in a 3D application (game, benchmark). Finally, I installed my old F-S Ati driver back (luckily I had saved it), and the crashes stopped.

Any thoughts why this happened to me? Is it something in the F-S BIOS? Is the fact that I have Windows Media Center as OS the reason? Or are Omega drivers simply unstable and their working depends on luck?

 

Omegas are heavily modified- I had problems with some of them too.
What saved me was NGO HQ Modified drivers
http://www.ngohq.com/home.php?page=ati

Since those are a bit old- 7.3 I use Mobility Mod on official Catalyst pack.
http://www.driverheaven.net/modtool/

EDIT: NGO HQ don't work with Vista just like Omega Drivers. Mobility Mod on the other hand works fine with it.

 

Thank you for the encouragement. I was aware of DriverHeaven's Mobility Modder before but Omega drivers just seemed to be the popular choice. Anyway, I downloaded Mobility Modder and Catalyst 7.7, and installed... Voila. Everything worked and my system hasn't crashed. However, my CSS Stress Test scores went down from 109fps to 93fps. The important, on the other hand, is that now I have new drivers.

So thank you!

EDIT: The installation did have one tricky part as I wasn't sure which folder to modify (how many subfolders do I need to open). However, I stopped at the first "driver" folder, and everything worked out.

 

Someone posted me a link to Mobility Catalyst 7.8 drivers, and after installing them everything seems fine (with benchmark scores being the same as with my previous drivers, Catalyst 7.7+Mobility Modder). Previously I wasn't able to download the drivers from Ati website as Ati's compability program said the drivers aren't compatible with my system (probably because I have Win Media Center OS).

UPDATE: Wouldn't you know it, my system started crashing. First, it crashed when I was playing CSS, and then when I ran a benchmark program. In conclusion, I DO NOT recommend you use the latest Mobility Catalyst drivers if you have a similar system (especially if you have Windows Media Center). I download the new Catalyst 7.8 drivers and installed them using Mobility Modder, and my system is running smooth (although you might want to try out older Catalyst versions as benchmark scores seem to be slightly going down after each new Catalyst driver).