So, Acrobits is finally upgraded to iOS4 background capability - but, we learn, Apple has imposed significant limitations on how this can work.

I've been waiting for a fully functional SIP client since iPhone day 1!
Oddly, when I first tried the new version last night from home, connecting to my work SIP server via VPN, backgrounding worked?? I guess the conversion to TLS over the VPN must be working? It won't work here at the office now, even with the VPN over 3g though.
Anyhow, I am going to look into updating our Asterisk server to support TCP transport, but in the meantime, I'd at least like to be able to force it to stay awake in the background to receive calls, but this is not working. I get a pop-up notification, but no sound (no ringer) and when I choose Answer, it brings me into the program, but just to the keypad - the call is not answered and there is no Answer button on the screen. Thoughts?