I have a similar issue, the error is on "An unexpected error occurred
on a receive" rathan than "sent". I was able to workaround the problem
by increasing the "Connection timeout" (IIS Manager -> Web Site ->
Properities).
The error also happens with both sync and async call, and it only
happens on Win2003 with IIS 6.0 (not on WinXP with .Net 1.1). You can
see more detail in link I posted below. I posted a question yesterday
and hopefully I will get some reply.
http://groups.google.com/groups?hl=e...3DN%26tab%3Dwg