Debian users reported that when they're running non-xinerama dual head mode, xfce4-panel crashes when trying to move it to the other screen.
According to Julien Danjour (in the debian bug report), it shouldn't even be possible to move the panel from one monitor to another. In any case, the option should be disabled, and panel shouldn't crash but warn it's not possible.
I set the version to 4.4.1 but it crash in 4.4.2 too.
Thanks for your time,
Any change you can find someone to test this with the new panel on a similar setup? Moving between screens should work, between displays won't.
It might be hard to find testers at the moment (without proper packages I can't really ask an user to rebuild all the plugin himself). I'll try to keep you posted as soon as we've come up with the migration plan.
Going to close this bug. New panel should be better in this (since all screen-depend plugins watch screen changes) and the bug needs to be more specific (ie. panel itself segfaults, launcher plugin, ... etc).