AIC not instantiated under load

Hi,

I am having problems with an AIC that I have built in C#.
The AIC has been placed in COM+.
The problem only arises when I have the AIC being called simultaneously by
BizTalk around 5 - 10 times.
BizTalk logs the error "Object reference not set to an instance of an
object".  It is as if BizTalk can only create a certain few instances of
the
object before COM+ will not allow any more to be created.
The Pool size in COM+ was originally set to 1 (default), but I found
changing this to 10 made no difference.

Does this sound like a COM+ configuration? Or a coding issue?
The AIC dll actually contains 2 different AIC components, both of which
are
having the same issue.

The full error message from the event log is below:

========================================================================
Event Type: Error
Event Source: BizTalk Server
Event Category: Do***ent Processing
Event ID: 324
Date:  7/01/2004
Time:  1:51:51 PM
User:  N/A
Computer: WORKSTATION01
Description:
An error occurred in BizTalk Server.

 Details:
 ------------------------------
 [0x80004003] Object reference not set to an instance of an object.
 [0x0159] The server encountered a trans****t error while processing the
messaging ****t "Test****t", which uses a trans****t component with a ProgID
of
"Testing.TestAic".

 [0x012a] All retry transmissions failed.

 [0x80004003] Invalid pointer

 [0x0156] The server could not finish processing messaging ****t
"Test****t".

 [0x1730] Suspended Queue ID: "{3CCCDEEB-BF5D-4083-A632-FFB5C7EF6B1A}"

 [0x80004003] Invalid pointer

For more information, see Help and Sup****t Center at
http://go.microsoft.com/fwlink/events.asp.
========================================================================

Any help appreciated!

Thanks,

Bardo.