Just a heads up for anyone else seeing this problem, as the long awaited Froyo (Android 2.2) is dropping to devices we've seen an issue with the self-signed certificate. It will fail on adding an account on the device with an "error connecting to server." No details, just a generic error. Nothing in the logs on phone or server.

The problem stems from the self-signed certificate not having the Mobility Server's DNS name as the CN. There is a glitch in the Froyo SSL library (known as an open bug in the Android bugtrack - Google claims "unable to reproduce") that causes problems if a certificate is encountered whose CN doesn't match the site even if you tell it to accept all certificates.

Quick 'n easy solution found after two hours of colorful swearing at the phone: make a certificate through YAST and export it as a .pem file. Use that in the YAST Datasync configuration instead of the self-signed certificate. It'll work fine.