Radeon 4670 : games crash - ACEE

Hello All,

I would appreciate your advice on this.
I am experiencing repeated game crashes, and Catalyst also crashes sometimes at startup.

Mobo Gigabyte GA-EP45-DS3R bios F10
RAM 1x2GB Muskin
Sapphire ATI Radeon 4670
Windows XP SP3
Catalyst 8.8 (bundled with card)
Game: Homeworld 2 (i know, it's old...)
The system was built a week ago and seems to work ok otherwise (video coding etc.)

I tried to update graphics drivers: Catalyst 8.9 didn't work, and Sapphire removed it from the 4670 section of their site today.
Nothing either at amd.

1. Updating the bios, etc. using gigabytes' utility
2. Turning on or off power saving features.
3. complete uninstall/reinstall of driver&catalyst
-> did not change the problem.
4. Lowering graphical details (reset to factory defaults) made the issue occur somewhat less frequently - still once every 1 1/2h maybe.

Then I noticed in the ACEE events viewer, a lot of messages, with timestamp matching the moment when the game crashes:
"Set OD5 fan speed fail".

It definitely looks like a driver problem.
There seems to be vey little literature online about this. Please see:
"set od5 fan speed epm fail" - Google Search

And about drivers for the 4670:
AMD Game Forums - Where are the drivers for Radeon HD 4670?

Do you have any idea ? Or shall i just wait till amd issues the next magic driver version ?

Thanks a lot for your help !!
Antoine