callback failure from threads?

[locklist <locklist IfA Hawaii Edu>]

I get a string of warnings that seem to (but may not be) lead up to a 
failure.

The failure is with a server using orbit2 on RH9, the client is a 
written in Java 1.4.2.

On connect I get:
** (process:5759): WARNING **: Ignoring incoming code_sets component

but everything seems fine.

Then I do a series of calls from the client.  Each call sets up a 
function pointer on the server, and wakes a thread to perform the 
function, then returns.  On the server side, once the woken thread 
finishes it's task, it calls a callback function on the client, then 
goes to sleep.

The first time I call the function on the server, everything works as 
expected, except I get a warning from the server when it performs the 
callback:
  
(process:5759): GLib-WARNING **: g_main_context_prepare(): main loop 
already active in another thread

The second time I call the function on the server, the server seems to 
stall or freeze, until I hit the return key, which seems to stimulate it 
into working.  It seems to do the right thing, though it gives me the 
same warning:

(process:5759): GLib-WARNING **: g_main_context_prepare(): main loop 
already active in another thread

The third time I call the function on the server, it usually fails, 
giving me the error:

GLib-ERROR **: file gmain.c: line 1621 (g_main_dispatch): assertion 
failed: (source)
aborting...
Aborted

However, sometimes it just stalls, until I hit the return key again 
(this hitting the return key business is happening in the terminal that 
starts the server).

And sometimes it works semi-consistently after I hit the return key a 
bunch of times, and I have to go for a long time before the error occurs 
again.

I'd seen a post relating to a similar error a couple of years ago, but 
there was no attempt to resolve that.  Does anybody have any ideas as to 
what might be going on?

The general outline of the server is:
start three threads, each thread talks to a mechanism.  each thread 
sleeps on a mutex/conditional.
initialize the corba connection and process calls from the client.

calls from the client set up a function pointer and then wake the 
apropriate thread to perform that function, which typically involves 
controlling a motor/moving a mechanism.  Once the mechanism has been 
correctly adjusted, the thread calls a callback function, then goes back 
to sleep.

Thanks in advance,

-Charles Lockhart