When moving/resizing/cycling windows, X seems to lock up. The mouse and keyboard seem unresponive, the system looks locked up.
This is because of the commit in rev. 22296. The attached patch fixes the issue.
Created attachment 661
That bug is fixed in SVN. Use either revision 22422 or later from SVN, or download a recent snapshot of xfwm4 from http://www.foo-projects.org/~olivier/preview/