Hi Oshyan
Think I have it now, I was making some simple fundamental errors when exporting data from global mapper, building up a number of files in different formats, so took a little time out, deleted everything, other than the raw data, and started again, downloaded a demo of geographic imager, in order to tidy up edges, and everything seems to be good now. Vue:, yes OBJ via global mapper dxf export, and 3d studio max, but realy didnt want to do it this way, as its a lot of faf!
The job is for a client, most of the high rez data is what we have collected/created, and the client will just drop the full brief on me in a few weeks, so need to get the basic terrain sorted, all the extra stuff, such as bringing in models(obJ)ie buildings, trees, and a few other things, i am fine with as well as populating via texture maps or painting, as I have done this a number of times with generic landscapes. so looks like all is good in the world again
I think the main issues were becaus ethe data we created was very irregular in shape, so by bringing in base 2 terrains also brought in invalid data, hense the messy edges, now I have some basic low rez terrain in the background of what I have experted, blended in photoshop, via geographic imager, and done that way, so I have 2 terrains that now fit neatly together, before bringing into terragen, its a bit of a lesson for me, get the data right, dont blame the software
will post an image, when i have the main set up done
cheers