Anyone have a recommendation for a SIP client on a Windows Mobile 5 device - specifically an iPAQ RX4000?

I have previously used SJphone on a Windows Mobile 2003SE device (Harrier) which worked just fine, but I no longer have a functioning wi-fi card for that, which is how I'm wanting to use it. Unfortunately the beta version of SJphone for WM5 devices on an iPAQ suffers from the problem that the microphone input is not detected, which appears to be a common problem with a range of HP WM devices from looking at their forums. Incoming audio works just fine. Obviously a problem with SJphone, because Skype has no issues with microphone input.

I found an old copy of X-Lite, but could not get that working at all.