Thanks, deedee.

Touch wood, I may have worked it out. I was on the phone with Vonage for quite a while today. They confirmed that our bandwidth was too low and our latency was too high. . .and that Qtel (hello Qtel, are you listening?) had mucked around with the available bandwidth in Qatar.

They were able to adjust my "packetization" and I did have a clear (normal) call tonight. Fingers crossed that it stays that way, though I'm not holding my breath.

I called Qtel today as well (before things cleared up) and they continue to claim that they're "still trying to locate the problem". Whatever, Qtel.