Cannot sign in to Microsoft Account on Windows 8 Phone

Hi - I hope this is the right place for this, I did not see a Windows 8 Phone forum...

I have an HTC PMM23300 phone on TMobile. I've been trying for weeks to get it to sign in to my Microsoft account. But whenever I try, it tells me "Can't Connect. We're having a problem signing in. Make sure you have good reception. If you do, the problem may be on the other end. Wait a little while and try again."

Well... I've certainly tried waiting. I've tried resetting the phone. I've tried resetting the phone to factory settings in case it is in a "bad state" as Microsoft suggests... but still no go. It does it on WiFi and on cell data.

Anyone have any suggestions to help? I like the phone, but I'm ready to get rid of it and go back to an iPhone... things shouldn't be this hard.

Thanks in advance!