iCall has a lot of bugs which they had said they were working on. They had been beta-testing a new version by private invitation. If anyone was fortunate enough to get the beta version, would you be kind enough to post a download link?
In the meantime, Earthcaller has been suggested for outgoing calls to Canada/U.S. I have tested it a bit and the quality is good.
As for incoming calls, you can try www.tpad.com I've been having trouble with it and emailed tech support, but maybe you'll have better luck than me. You get an extension number but there are fewer Canadian access numbers than iCall, only Toronto and Vancouver.