Irratic motorized seat belt

I was only refering the problem below:

Oh no. I meant it's always the ECU if the seatbelts only work with the keys in the ignition

It seams to be the numebr one seatbelt problem of svx';s

Kuoh....I had the same problem you did. Seatbelt would get jammed everytime and a nice hit would break it loose. I ripped apart the car and it turned out the wire cable that drives the seatbelt back and forth on the track became slightly un-twisted which caused the seatbelt to jam. I re-twisted it with a pair of pliers and re-assemled and it has worked flawlessly for over a year now. Might want to give it a try.