Lock for wagon rear hatch won't open

The lock for the rear hatch on our 2000 Passat Wagon will not turn. It has been finicky for a while, where it was a bit reluctant to turn. And the rear hatch has a strange handle for opening where you pull two tabs rather than use a standard door handle-type latch.

In any event, does anyone know if this is a common problem? Should I simply order an entire new lock mechanism for the rear hatch and wait for it to happen again in a couple of years? Any feedback would be much appreciated.

Thanks!

This thread covers it fairly well. It's a very good site for the late model Passat owner.

http://www.passatworld.com/forums/showthread.php?t=118849&highlight=hatch+handle