Wouldn't you know it! A friend of mine with a 98.5 SVT called me yesterday with the exact same problem. Well he was pulling up to a light and when he disengaged the clutch, the car shut off.
He could not get it restarted for anything. After getting it back to his house, he checked over all the fuses and found that the ABS fuse was blowen. Knowing that it was unrelated, he changed it out anyway. The car of course still would not start. He calls me and is telling me what all he had done up til this point. I ask him to turn it over a few times so that I could hear it (tring to tell if the engine was turning faster then normal) and it cranked right up! Go figure!
I talked to him tonight and he told me that the car did not give him a single problem today, but I told him to be on the look out. Things like this just don't happen once. He is coming over Saturday morning so I can clean his UIM/LIM anyway, so I will look at it further then and see if I can find anything. If I do, I will let you know.