Invitiation could not be sent because of high security mode?

[joe_user]

I've looked high and low for an answer to this and can't find any reasoning.

Using Windows Messenger v5.0 (5.0.0381) with a Communications Service set up only, no .Net. I can make outbound phone calls, video conferencing, etc. just fine. However - any time someone connects to me INBOUND it never works and I get this message:

"Your invitation could not be sent because your program is not configured to allow peer-to-peer calls while in high security mode"

And it will never allow inbound connections. This is happening on 2 different PC's that were upgraded from 4.7, one an XP SP1 laptop and the other is an XP SP1 Tablet PC. Both of these devices could send and receive calls just fine before upgrading.

I've tried reinstalling, changing IE security settings to LOW, setting permissions to Everyone/ALL on files... nothing works. I know for a fact it's not the connection because this has happened in lots of places where other devices on the same LAN can init
iate and receive fine. It's definitely something in the software.

Any ideas?

Thanks.
Joe