ODO woes

[ausgolfer]

Hey people, I have a weird and wonderfull problem with my passat, I know it's not a mk2 golf, but it's a 90 model so I figured it will get the most love in this section.
Now the problem is the ODO rather than registering one km as one km, is registering 100m as 100km, see the pictures for proof.
Any suggestions on how to fix this? As the old passat has covered about 40 thousand kms in the space of 2 months(or so) driving, could possibly make it the worlds fastest passat. Some pics taken seconds apart, some taken a few mins apart.

260964kms at 22:36

261064kms at 22:36

261164kms at 22:36

262764kms at 23:01
Cheers Carl.