No FPS change in highest or lowest Resolution (RAD9700)

This is it;

When I change resolutions, from the best, to the lowest, there is no change in FPS. Also when I turn all effects off or on low, it doesn't improve the fps. I get this in all games to not just RavenShield.

Any thoughts? I really would like to turn the res down to get more fps but that'd be to easy huh.

I am gonna email sapphire now, so any other help is greatly appreciated.

Oh and before you say I have updated everything on my PC,AGP,IDE ,bios, gfx card drivers, and I have done all the tweaks.

My fps is only really bad when playing with other team members in single player and adverserial modes.

In coop my fps is ok 30 - like 50. But any mode that requires the cpu to think about the ai and I am stuffed.

But there are people with poorer pc's than mine getting better FPS, so I thought I would try my best to sort it out.

And my system specs were at the bottom of my post.

I get severe lag in adverserial and campaign modes,it's really unplayable, I need to sort it cus I'm playing in a clan and it does make a difference. Whats tiks me off most is the fact of when the fps jump from high smooth frames, to low and jerky.

2.4ghz p4
768mb ddr 2100
epox 4sdm2+
sis 650
saphire radeon 9700pro