Sandbox Stamptool mess up soften geometry

[thomthom]

I made a sandbox terrain. Draped some existing roads onto it, Added colours. Looked good.
Then I stamped a new road onto it and for some reason lots of lines all over the terrain is now hard. Even though they're far outside the stamp radius they somehow changed.
I can't just select the whole mesh again and use the Smooth tool because that'd mess ut the various materials which I've painted. Some the the existing lines are just coloured edges and they'll disappear.

Anyone else experienced such problems with the Stamp tool? Any workarounds?

[remus]

I havent had this with the stamp tool before, but i have had problems with grouping/ungrouping subsmoothed geometry. No idea why it does it

Not sure why softening the edges is causing the model to lose its colour either, it stays put in my little experimets.