I have had no luck getting Visual Voicemail to work on an iPhone 3G, running 3.0 Beta 5 on O2 UK. I get a message "Voicemail Unavailable - Unable to initiate connection". I get this message with great 3G coverage and wifi. I have tried restarting my iPhone, no joy, and also changing the PIN (which I have read has fixed this issue in the past) - changing over the phone does nothing, changing it in the Settings > Phone settings gets an error message similar to the previous one. Any ideas?