I've had the same exact problem. The SAME exact problem. I'm glad you wrote it up and I got to read it though, for it seems I may have 'fixed it' a little.
Just to know, my other 6700 never did this, it had the 1.43 radio and 3.14.00 WWE rom on it with WM5.
This 'new' 6700 (new to me) came with the 1.12.00 radio and 2.06.00 WWE Rom. I flashed to Pheonix's 1.41 radio and instead of waiting 30+ seconds to dial out (could dial in no prob), I know wait ~ 5 seconds or less. I hope it stays this way, for I did this ~ 2 hours ago and have tried many calls. Try doing that, here is the link:
http://forum.ppcgeeks.com/showthread.php?t=5964
Cheers
-Rob
P.S to O.P: I still have not updated my ROM version 2.06.00, though I would like to. Perhaps you can help me with that?