@fizz
i have an OBi100 where i had this problem. (i don't have the OBi110 since i don't have a landline to plug into it.) and similar to your problem with randomly missing calls that go straight to voicemail, the calls for me would not ring on each and every incoming GV call on the phone connected to my OBi100 although the caller would hear the rings. my solution is to have GV forward to a Sipgate number, and uncheck Google Chat in GV settings, and have GV as SP1 on my OBi100 for only outgoing calls, and have Sipgate on SP2 for only taking incoming calls from GV. it's a google problem as far as i can tell because this "ring, no-ring" problem also happens in Gmail for me. i've tried it with Gmail open in a browser and with no Gmail open in a browser. i've also tried it with Google Chat not logged in while in Gmail to see if that would make the call ring on the phone connected to my OBi100. but the same random "ring, no-ring" problem was still occurring. and this was even happening when using the same phones (at&t, tmobile) to make numerous test calls with Gmail open, not open, Google Chat logged in, not logged in, and other different combinations in GV settings that i've tried, etc. etc. etc. many many times. so my solution is to not forward to Google Chat and just have Sipgate handle the incoming GV calls on my OBi100. of course, i can't answer calls in Gmail anymore, but that wasn't really working all the time for me anyways (so if i want to take incoming calls on my computer, i could always turn on the sipgate software). i have a review on the amazon page for the OBi100 where i talk about how i've set up GV with Sipgate on my OBi100. you can use any sip as a substitute for google-chat on the incoming calls, but i got a free sipgate since you can get a free account for just the incoming calls.
