QuArK (or max2dif) exporting problem

I've never really had this problem before, but I've never worked on something this precise before either.

I'm modelling a house to scale. The problem I have is that everything is perfect in QuArK, all my seams are accurate, but when I export the .map and .dif files, there are gaps between the seams. Not all the seams, just between the roof and the walls. Since these are the only 'angles' I assume its a mathematical problem with QuArK calculating decimals for angles?

Is there anything I can do, like find an updated exporter? I open the .map file in Constructor, and the gaps are small, but there are so many of them that it'll take forever to find them all.

If I have to start over again in Constructor I will, but I'm not as familiar with it as I am with QuArK.

HELP!!!!

thanks,
Tony