Missing ground in snow valley

[Andromedax]

Same problem here, (got an ATI RADEON 2600 PRO)

I browsed through the forums and tried the following solutions, none of them worked :

- Installing patch 1.0.3
- Disabling ATI A.I.
- Upgrading my drivers (well they were already up to date)
- Downgrading my drivers

Any ideas ?