Palm Clients will not connect through Proxy

[Dorowan]

Hello!
I have tested the stable version and the most recent beta (2.9.9.3) of the palm client. Both versions will not connect through the proxy my mobile provider wants me to use. I tried to connect via https. If I turn the proxy of I can reach the Sync-Server (tried eGroupware and c't-Synthesis). If I use the proxy (http proxy on port 8080) I only get an connection error after some changes between "sending..." and "waiting...".

Might it be problem that it is only a web/wap-proxy? I thought SyncML is http only.

Greets,
Carsten