Level-D Clock Problem

Hi,

Recently bought the Level-D 767 for P3D and very impressed with it so far, considering how dated it is. The one thing I'm stuck on is the chrono in the VC. When I start the F/O's one when pushing back and the Captain's when taking off, the clock starts correctly on 0 and displays the elapsed time correctly until about an hour in. It's from this point onwards that the clock starts to display weird numbers instead of what it should do.

For example, after about an hour and a half into a flight from Athens to LHR, it read 73 on one clock and 8 on the other. When I finally landed and stopped the clocks, both displayed '18' on their displays. I looked at the timings and it was a 3 hour and 10 minute flight, so the clocks were displaying something very different!

Does anyone know why the clocks are being so odd? They haven't once displayed a 1:03 or something like that to denote an hour elapse, instead they just show 73 to show 73 minutes.

Thanks in advance.