I don't know if this provides any helpful information concerning the stalling problem, but I had my first and only potential related issue on Friday.
Situation was as follows: soaking wet roads due to recent rain, temps in the low 80s with high humidity, and I got stuck in stop and go traffic for about an hour. The Tiger got very, very hot -- coolant temp never got above the usual level, but there was a high level of heat coming off the engine and frame. After a while, the idle, which has always been quite steady at about 1100rpm, started fluctuating a bit, and I found the bike a little reluctant to rev when letting out the clutch (found myself having to give it a little more gas than usual and let out the clutch a little more slowly). Eventually traffic cleared up and I got moving again, but even after riding on open roads for ten or fifteen minutes with plenty of airflow to cool the bike off a bit, the idle would still fluctuate when pulling up to stop signs, and once dipped down below 800rpm as though it was about to die, but I blipped the throttle in time to keep it running (lots of practice at this -- I own a Bonneville, which requires the same technique before it's thoroughly warmed up).
After turning the bike off and letting it sit for ten or fifteen minutes, it restarted normally, and while the idle wasn't spot on, it only fluctuated by 100rpm or so. After letting it sit for 20 minutes or so, it ran normally.
And Saturday I took it for a 300-mile ride (during which I turned over 10,000 miles) and it ran perfectly normally all day.
What I take away from this is that the problem is caused by excessive heat, on my bike at least -- and it would not surprise me to learn that the stepper motor is the culprit. Perhaps it just can't take getting that hot. Under normal conditions, there's more than enough airflow to keep things at a reasonable temperature, but in stop and go traffic, the engine ends up throwing off so much heat that all the electronics cook.