I noticed that highest resolution you can cap is 328x244 sample=1 and 656x488 sample=2
Try those settings and check if your screenies wont look some what better.
I found a fairly strange cheat, you can detect it with ping plotter.
It's probebly a faulty (by accident ;-") Firewall.
When you detect that your shooting at someone and don't hit him as you should.
Ping 30 feels like ping 1000. You have to lead very much, but he got low ping.
But every time he hits you it's strangly enough do twice the damage.
Seems like they stop some packets in firewall and send twice as many.
You need to have a computer as a firewall when using this cheat.
Then you could sort out what packets going through wall and how many of every that you sent should be sent x2 or x4 and so on.
Detection very hard if you don't check his IP with PP.
And even then it's very hard to detect.
I started notice it when I turned down sniper bullets to 60% damage for a headshoot.
Spawn and die from a sniper in one shoot = there you go.
When nicly asking a teammate of his if there is more then one sniper, and there isn't you can be sure.
To be able to detect cheats you have to know how they work.
A catch22 thing
So it would be nice if this site could help us detect cheats, what to look for and how to look.
When I see something strange I usually go spectator on his ass and screenshots like crazy.
If you see one person dissconnect every time someone go spectator, ban him.
You can change to his team and deathcam him, hidden spec mode.
Before you go spectator copy player to clipboard.
Punkbuster do a good job actually.
Someone that hates cheating and team stacking.