GNU Cash: some keyboard keys don't work

I marked this as "normal" priority, but I think that it is critical for people who use GNU Cash. This bug makes GNU Cash unusable.

The problem relates to the input method. Disabling IBus (that runs by default) fixes it (after a disconnection/reconnection from/to the graphical session):
$ echo 'export XMODIFIERS=@im=none' > ~/.xprofile

I'm sorry, but this is not a usable workaround. It requires me to disable my input methods while using GnuCash, then re-enabling them afterwards. I suppose being in a monolingual computing environment would make my life easier, but I shouldn't need to disable language inputs in order to use any software.