Vista - Messenger on MSN.com vs. Live.com: Error 80072efd

I have two Windows IDs, one @msn.com and one @live.com. I've had the msn.com account for many years, the live.com account less than a week. The IDs are linked. Recently I downloaded and installed WL Messenger and other WL tools using the msn.com account. When I attempt to sing in to Messenger on the msn.com account, a dialog box appears indicating that the service is unavailable. Sign-in using the live.com account works fine, no problems. I went to Help on the msn.com Messenger sing-on and followed instructions to test the HTTP connection. The test results in error message 80072efd, "We are unable to connect."

All my contacts and messages are on the @msn.com account and I want to use Messenger on that account. Not the live.com account. Please advise.

Thank you.