Yes, with a little more time, it should start working. That "36 to 48 hours" was a rough guess on my part. I just know it takes a few days before the karma calculator begins showing the influence of Talk activity. It may take a bit longer than 48 hours, and no, I've no idea why there is such a delay.

Actually, judging by the number of times people have posted here reporting the linking of their accounts hasn't worked and then posted a followup the next day saying "nevermind", I've come to believe the best estimate of the delay is "24 hours after you've decided you must have done something wrong or the darn thing is broken".