Farcry 2 Issues (both performance and the MOUSE)

after getting my copy of farcry2 2 days ago, which i chose over gta4, i noticed some very weird weird WEIRD issues.

#1 : the in game benchmark software which is pretty useful btw, is acting silly. i tried 2 instances of the game both with dx9 and dx10, all details set to the highest possible only 2xAA and 8xAF (via ccc).

now with dx9, the results are:

* Average Framerate: 27.78
* Max. Framerate: 35.06
* Min. Framerate: 23.77

with dx10 the results are:

* Average Framerate: 38.30
* Max. Framerate: 50.67
* Min. Framerate: 29.91

catalyst 8.12 was used on this with q6600 @ 3.0ghz / p5k-se / 3gb RAM / hd4850 stock

so theres cleary a 10fps difference with dx10 having the upperhand, but you have to be "BLIND" or "DUMB" or just "PLAIN DUMB" to not notice the STUTTER at the beginning of the ranch level up to the part where you going to the roof. is this another one of those benchmark optimizations that both ati and nvidia have done in the past?

#2 and when im playing it doesnt feel like its faster at all with dx10. theres the mouse lag issue. ive googled around and the only fixed that i've found is a registry file which looks dubious. you guys know if theres another alternative with what they call "DX10 Mouse LAG?"