Problem with custom keyboards...

We have a custom Tongan keyboard built with Keyman 
(http://www.tavultesoft.com/). To produce the acute version of the 
vowels the users press the control key plus the vowel. For example 
ctrl+a = á.

The alt+vowel keys produce a macron (ā) and work fine with FireFox - 
however the ctrl+vowel keys produce nothing. It looks like the ctrl key 
events are being eaten by FireFox.

Our keyboard works in almost any Windows application you can name 
Notepad, WordPad, Word, and, should I say it... Internet Explorer.

Weʻve contacted Tavultesoft and they say that it is a problem with the 
application (Firefox 1.01).


Tavultesoft mentioned that Microsoft has published guidlines on how to 
make MS applications "keyboard friendly".

Is this a known problem? Any pointers on how to fix it? I would be happy 
to post a patch if I can get a head start from some developers familiar 
with the code.

J