Laggy and sticky keyboard in games.

[munsworth]

I am having problems when I'm trying to play games fullscreen with my keyboard and mouse. The keyboard sticks - I'll be 'walking' in game and it will continue until I double tap the direction key. Also the keyboard is not very responsive sometimes really laggy or not responding at all. Mouse is fine.
I've come across this problem in Minecraft for linux and Halflife source in steam for windows running in wine.
Any Ideas what I could do to correct this?

Linux Mint 14 64bit
1GB Ram
Pentium D 2.66 x2
Nvidia Geforce GT240 using nvidia-current driver
Logitech ex100 wireless mouse and keyboard connected via usb