CS 2007 Order Service Failure (COM+, Object Pooling)

I am getting a couple of odd error messages logged in the event viewer
when I attempt to call the SaveAsOrder() method on the Basket object.
Usually what happens is that the SaveAsOrder() succeeds, sometimes but
not always, only to have the aspnet worker process mysteriously
terminated.  Whether or not the SaveAsOrder() function call succeeds
or not, I am always met with the Service Unavailable message (aspnet
worker process is killed) and the same errors are logged into my event
viewer:

A condition has occurred that indicates this COM+ application is in an
unstable state or is not functioning correctly. Assertion Failure:
m_pTxResPool == NULL

Server Application ID: {D7D961C6-52DF-415A-9E57-F848F66DAF57}
Server Application Instance ID:
{CAECFA22-C4C9-4961-AA31-A34F4D8E93E4}
Server Application Name: Commerce Server Orders
The serious nature of this error has caused the process to terminate.
COM+ Services Internals Information:
File: d:\qxp_slp\com\com1x\src\comsvcs\txprop\txstream.cpp, Line: 608
Comsvcs.dll file version: ENU 2001.12.4414.308 shp

and...

Application image dump failed.
Server Application ID: {D7D961C6-52DF-415A-9E57-F848F66DAF57}
Server Application Instance ID:
{CAECFA22-C4C9-4961-AA31-A34F4D8E93E4}
Server Application Name: Commerce Server Orders
Error Code = 0x80004005 : Unspecified error
COM+ Services Internals Information:
File: d:\qxp_slp\com\com1x\src\shared\util\svcerr.cpp, Line: 1259

Now, I found a way around this problem and it is to turn off object
pooling for the Microsoft.CommerceServer.Internal.Orders.MtsTxHelper
component, but I don't believe I should have to do this.

Any ideas on why this is happening???