Red face Anyone have experience with VOIP? on HTC

Hi to all the HTC users, is there anyone out there that can help me with any information on how to setup VOIP on a SEDNA/P6500 and work it across the 3G network?

Have tried a few configurations and software, but still not connecting to my VOIP account. As soon as I make a data call then "Internet Calling is disabled" I know it must be able to be done, I use VOIP as my home phone and am trying to get the VOIP working across my mobile data carrier.

Any contributions would be gratefully received! Looking forward to reading other peoples experiences (and tips of course).