64-bit or 32 bit kernel? I've had issues running 32-bit OpenGL libs & especially OpenAL libs on the 64-bit sabayon kernel (though not gentoo) in the past (some versions ago mind, so my experience here is a little out of date).
As an indication - the client rarely crashes here (certainly no more than the windows version) and we have 2 machines, I can vouch for the following hardware:
nVidia GeForce 7300GT
PIV 3.2GHz
768MB Memory
(No idea of the specific board, some parts-bin packard bell job
)
and
nVidia GeForce 7600GS
PIV 3.0GHz (Hyperthread, single-core)
2GB Memory
Intel P965 Motherboard
Tried on Ubuntu 6.10, Mandriva 2007, SuSE 10.2, Debian 4.0, Gentoo 2006.1 (amd64) - each has their own quirks but all are stable - all running and smp kernel.
Upshot is, there is nothing wrong with your level of hardware for playing regnum (Even the 7300GT gfx handles all of the detail turned on _except_ the water and thats due to a bug, not H/W requirements) which means its probably down to a config problem, library conflict or the 32-bit translation layer somewhere.
You could try running in wine since you have a cursor now
- do you have any 32-bit openAL test programs - if they prove to be unstable it would narrow it down to one place....
Random thoughts:
How's alsa with your sound-card ? (I have to run OSS on the 965 motherboards on-board sound otherwise most games throw a fit over the sound in one way or another - Regnums no exception, but actually better than most with that)
Failing that - which drivers are your running for the graphics card ? I my experience nVidia's own 1-9xxx series are the most stable all round and the open source nv driver is about as desirable as the pneumonic plague.
Are you running Beryl or Compiz ? occasionally the compositing causes some problems with 3D games (heavily video driver sensitive) - with Beryl, just dropping the window manager to the native one sorts that out in a heartbeat (less experience with compiz, sorry).
Does Regnum pause for a long time on startup sometimes - thats indicative of a connection problem somwhere which may be down to a firewall router or your iptables setup.
There have been odd occasions when I've seen the download of various bits choke and cause issues with no discernable source - cleaning out your renum installation results in a painfully slow start next time but may be just the thing to sort the problem.
Finally, try checking the "Update all new resources at once" option at startup - again horribly slow the first time, but one consitant problem here is the client going awol if it's left to download on the fly - it seems to hate that for us.
Hope that helps a little.