Check your plugs on youe PC. Mine did the same thing to me on my 08 softail. Looked like they were connected but one was loose. Unplug them and reconnect. Worked for me, never happened again.
I had a stalling issue with my '07 FLHX. It started just as yours did, at stop lights. Of course when it took it in for repairs, they couldn't find any problem. When it eventually became bad enough to diagnose it was the ignition switch.
I had mine die day I picked it new and after much checking they fiund that the power commander was bad and had to order a new one.After replacing have not had any further problems with it shuting off.
I remember 3 differant problems on this forum, 1 was the ecm plug not seated like somebody here allready said, 2 fuel canister was a recall i think, 3 main breaker fails under heat.
I had the same thing happen with my 06 Ultra. It must have been fuel because it stopped after I refueled. It did happen one other time but again quit after a re fuel.
A friend of mine has an 08 Heritage and it did the same thing last weekend. He took it in and was told that was a common problem. They changed the heat sensor and it now runs great.
I guess I'll just go through a disconnect/reconnect session on everything electrical that I can reach tonight. Thanks for the input, leads, suggestions.