asterisk users - Mar 2004 - Incominglimit - SIP verses AIX, phone busy

Hi all,

Using Asterisk 0.7.2
Redhat 9, kernel 2.4.20-8
Two X100P interfaces

When I'm busy in the phone, I want Asterisk to detect this and
do +101 jump.

Using SIP phones and setting "incominglimit=1"  for a user in sip.conf
works great, astersisk beautifully detects a BUSY user and does +101 jump.

But using IAX2, this is not recognized at all. I have testes a few
IAX clients, among them - Firefly and DIAX, but I have not found any 
way around this problem. People think I'm ignoring calls despite that 
I'm busy in another call...


I have search the mailinglist and found nothingnn concrete through this. 
I found a bugtrack regarding this problem but only in regards to SIP
(http://bugs.digium.com/bug_view_page.php?bug_id=0000408)

I'd appreciate if anyone has a suggestion how this can be solved, 
either through patching, configuration or selecting a IAX-client that
can supply info to asterisk in such way that it understands I'm busy...

TIA

Regards 
Stig Andersson