I have made a cludgy hack to "solve" the problem. I haven't played around with it, but at least it will start now. I won't have Japanese input in Xara, but I can live without it, at least for now.

make a new file called xaralx.sh, and make it's contents like this:

#! /bin/bash
unset XMODIFIERS
unset GTK_IM_MODULE
unset QT_IM_MODULE
/usr/bin/xaralx &
export XMODIFIERS=@im=SCIM
export GTM_IM_MODULES=scim
export QT_IM_MODULES=scim


instead of running xaralx, use sh ./xaralx.sh

I certainly can't guarantee that this will work on every system. I does, however, make xara start on mine.