From the call log the correct number 1877xxxxxxx was being placed. I haven't tried dialing 877xxxxxxx. I'll give it a try tonight.
Yes, the number goes through fine if I dial through Google Talk on my computer. It also goes through fine if I dial out using the **8 prefix to use the landline. Just the Google Talk outbound through Obi is having problems.
For what it's worth, I'm calling a voice conference system which picks up on the first ring. I'm not sure why that would affect anything, but maybe it checks for something on the line and if it think it detects something odd, it hangs up. Not sure.