[winswitch] misaligned pointer

[Bob Tennent]

One issue I see with xpra-0.6.0-3 on Centos6.3 is that the window
"pointer" is about 60 pixels above the point it's really pointing at.
This is most evident when going down a menu and the highlighted entry is
the one *below* the pointer.  This is for a remote server.  I don't think
I'd had this with an earlier version but perhaps I never noticed it.

Bob T.