Does that happen in the cached or online mode? Does that happen when you
select many (hundreds) of messages?
What do your COM and ECE do? Especially h regards to the selected messages?

Dmitry Streblechenko (MVP)
http://www.dimastr.com/
OutlookSpy - Outlook, CDO
and MAPI Developer Tool

"Pete C" wrote in message
...
Hi Ken,

Thanks for your reply. We actually have both a COM addin and an ECE,
implemented in the same DLL. I wasn't sure if the error message was
related to the COM or ECE part - do you think it is definitely the ECE
part that is causing the message to appear? The ECE is registered
using an ECF file. We actually have a second ECE in a different DLL
which is registered through the registry (because that is the only way
to get certain functionality) but I'm not aware of a message coming up
for that one.

I will find out whether they use ESM later today. If not then I will
look into opening a support case with MS.

Regards,
Pete.