2000 jetta tdi 1.9 cylinder head

[mastertechlt1]

I am new to this web site, so I may take a while to get use to it. I have a 2000 jetta tdi 1.9. The timing belt skipped and was replaced by the local vw dealer. The car ran for about 3000 miles and the belt failed again. the dealer again installed a belt and claimed the belt was defective. After driving the car for about 700 miles it did it again. I decided the next step was to do the repairs ourselves. I own an upper end euro auto repair. We do some vw car but mostly bmw, mb, jag, and saabs.
The problem started when after replacing the belt, rollers and everything else the car ran great. It ran for about 4000 miles and dropped the # 1 intake valve. Im not sure but one of the times the t-belt jumped time it might have hit the valve and caused it to fail. I didn't show until it dropped the valve. We removed the cylinder head and took it to our local machine shop. They inspected the head and said they could repair it. We replaced all valves (not to take any chances) new lifters and cam. We installed the head and it ran great for about 20 minutes. My tech took the car out for a drive and it dropped another valve (new valve) on the # 2 cylinder, intake. Ok I'm thinking maybe defective valve, (it broke just under the keepers). I contacted my supplier and we were sent new valves (TRW) and installed all of them again. Now I'm not a betting man but I would have thought everything would have gone great EXCEPT we had the car running again it ran for about 10 minutes. Smooth quiet (for a diesel). Left it @ idle and it began to tap loudly and misfire on the # 4 cylinder. We shut it down and before the engine could stop turning it locked up. It dropped another intake valve on the # 4 cylinder. Ok now the question, The machine shop said that they resurfaced the head. I was told today that the head is now no good because of clearence issues. I have now been told the valves and pistons are hitting. Any ideas on this or information would be great.
Thanks

[Fatmobile]

Wrong head gasket?