NFS Underground/Underground 2 with G11

Hi everyone

Since I bough my Logitech G11 keyboard, i have problems playing Need for Speed Underground and Need for Speed Underground 2 (NFS U/NFS U2 tried both with/without patch), before that, I did'nt have this problem. i have these games since they came out. The problem appears when I want to: go to pause-menu ("Esc" default), want to see the map, just before a race start, etc... the game freeze for about 10-15 seconds then continue it's sequence. I tried other keyboards (PS/2) but the probleme stays the same. My other games (racing, FPS, old and new) work just fine, no problemes. If you have any ideas, help would be appreciated. Thanks in advanced.

My pc:
Windows XP pro SP/2, AMD 2500+, 1 gig ram, Asus A7N8X-e deluxe, G-Force 6600 256 mgs, Logitech MOMO, Logitech G11, Logitech MX510