CTRL + F5 (used to force download of new images while browsing in firefox) causes the workspace to change instead. This isn't exactly a bug per se, but more of an annoyance. I'd recommend just having a preference setting to enable/disable this behavior.
you can simply unmap CTRL+F5, by editing the keythemerc file
All of these key shortcuts are customizable in xfwm4, if it interefere with app X or Y, just change either the setting in xfwm4, app X or app Y.
mass closing some old resolved bugs; please reopen if in error