Thanks for the info, that's interesting. I'm also using 1.2.1 but later build 2289. May be it is a bug of this build? It seems unlikely, right?
Actually I have one other issue, I'm not sure if they're related.
When I set GV as a primary line for outgoing calls, then both pure number dial and **1<number> works OK placing a call with GV, but **2<number> doesn't work i.e. it is not placing call with sip provider. But when I set sip provider as a primary line, then pure number dial still doesn't work!!! However **2<number> works OK. I believe it should not be that way?