Small issue of Xgl or wobbly plugin?

[Rockmen Jack]

Hi,all
	When I play around wobbly plugin of compiz,I found a small issue,that
is when a window is static(I mean content of the client area of the window is 
not changing),I drag it from one corner to another in a suddent,the animation
is not so smooth,it may freeze for 0.x sec(It won't happen if I move the cursor
constantly).But if the content of the client area is changing,for example,output
in a gnome-terminal is changing,animation works smoothly.
	Thanks all.