problem merging layouts

[markbin]

Hi ,
When i tried to merg 2 layouts ( a +- 100 baseboards one with a new 10 baseboards part ) i got a 20 m wide gap between the 2 .
Its DEM terain and the DEM contours fit , but for some reason there is 20 meters gone from the big layout .
There are no objects sticking out the layout borders who might disturb the merging proces.
What can be the reason ?

 

[markbin]

I found a solution .
I have merged in TRS2006 ; that worked; and then imported the map in TRS2004.
I am using TRS2004 because i want to use steamtraction on that layout.