Since upgrading to Update Pack 5, ALT-TAB in Remmina (the VNC client) doesn't always work correctly, even with grab keyboard turned on. Sometimes, randomly, the ALT-TAB "escapes" into the desktop on my local machine rather than the desktop on my remote machine. If I hit ALT-TAB enough times, it "pops back" into Remmina and then it will work for a while.
I was hoping that there was some pattern -- like a pop-up happening on my local machine desktop or some other screen event -- that would precede the behavior, but I am unable to find a pattern.
I'm using http://debian.linuxmint.com/latest for my main repository.
Is there something I can do to fix this, or, assuming that a fix is made upstream, do I need to wait for the next Update Pack?