I did have a very minor issue with ion3 when using alternate xkb groups. You may want to read the bug report I filed in the DBTS, if you are interested in this. [http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=414974]
Summary (from someone who is not really familiar with X programming): X sets some additional bits in the XKeyEvent.state when you use an alternate xkb group. Thanks for making ion! Andreas
