The default double-click speed set in the mouse preferences does not reflect the actual gtk2 or gnome desktop double-click speed
more info: after login the 0.4 sec double-click delay is not set. I have to manually open mouse preferences and move the double-click toggle back and forth to set the 0.4 delay. This setting however is not kept across logins.
Probably a control-center problem. (Haven't tried yet to reproduce)
Filed upstream as http://bugzilla.gnome.org/show_bug.cgi?id=103601, fixed in GNOME CVS.
Should be OK in gtk2-2.2.1