2006 Skoda Roomster weird electric window fault

My car was parked up for several week then I got in on a hot day and noticed the passenger electric window had stopped working from both switches. I had the same fault on the drivers side about two years age and which I managed to sort myself. (my local Skoda dealer had the car to diagnose the fault and was worse than useless ~ they said it was a broken wire in the loom and after checking all the wires I could I decided to change the window motor and this cured the problem }
Anyway this problem seems different I unplugged the connector that goes to the motor and it worked. Great I thought, I built the door back up, and it stopped working again. Then I worked out that if I remove the fuse for that window and put it back in again, it works for a couple of minuets ( but only from the passenger switch} then stops. I tried this several times and I got the same result every time. I don't think its the motor nor a dirty fuse as mine all look perfectly clean.
any ideas?.