there is currently an issue with AvP and Ram allocation, Rebel are addressing the situation and will be bringing out a patch shortly.
TRY - 1. Turning Texture quaility down2. Turning off mouse lag (in controls options)
If all else fails then run Dx9. There is only issues with DX10 and some on DX11 rigs. (ati)
Hope this helps,- PS,. if you wanna join in on some friendly MP matches join us at Link.
Please no cheating in multiplayer games thought . thanks