Internet_45 Error when using ActiveSync

[spiego]

When trying to use activesync via GPRS to our corporate email, I get the Intenet_45 message, which states that "The security certificate on the server is invalid." However, that is not the case for we purchased a certificate via Equifax and it is good until next year. The server is running Exchange 2003 and the mobile device is running Pocket PC 2003. What is the solution to overcoming this error?

Thanks for your input.