Here is an ebay source for the prone to fail door microswitch.

http://cgi.ebay.de/ws/eBayISAPI.dll?ViewItem&item=160371346069&ssPageNam e=ADME:B:FSELE:1123

Ebay user: carlicious-parts

I'm sure Jaycar or someone would have something similar here.

At least this is what it looks like so someone might be able to match up a local equivalent and post the details.

Much cheaper than a new door lock!