CTRL+W gesture sometimes doesn't work for Maxthon 2 tab closing...

CTRL+W gesture sometimes doesn't work for Maxthon 2 browser tab closing. Most of the time it works, but sometimes I have to do the gesture repeatedly to get it to work--and it's not because my computer is busy. Manually pressing CTRL+W on the keyboard works always--just not the gesture. I've tried settings the appication identifier for Maxthon 2 to window class, .exe, and tried variations of CTRL+W gesture like adding 100-200ms delay before CTRL+W in the gesture but it doesn't fix it. This problem doesn't occur to my Maxthon 1 CTRL+W tab closing gesture. Anyone have any ideas?

I'm on WinXP SP2, Athlon 64 4000+ CPU, 3 GB RAM.

btw: i also have maxthon 2's built-in mouse gesture disabled