East Prussia issues

[andyinkuwait]

I have been looking at East Prussia introductory scenario to try to understand MP better.

Here's the one problem I have: 

On the F4 Parameter File, it says 4 MP for a Secondary Road and 1 MP for a Medium Bridge. This is Horses in Travel Mode

When I do a trial move across a Medium Bridge through a Secondary Road, the system tells me I have used 4 MP but it should be 5 MP. 

It looks like the system is assuming the Medium Bridge is the same as a Heavy Bridge and has MP 0.

Can anyone explain ?

EDIT: Apparently Roads negate all other TEM as long as you stay within the road stacking limit. If you don't then the 1 MP comes into play for the bridge.