I am running Canada Post shipping, but can't add any pricing modules (wholesale, MSRP etc)

If I get the pricing modules going, Canada Post drops out (weight and dimensions)

when I re install Canada Post, the other add on's stop working.

I tried using winmerge (just hope I used it properly, can someone give a very quick rundown on how to do that)

It still didn't work.

Please help.

Guy