Of all the classes of cars I've tried the DTM seem most prone to being tripped up by kerbing. There are several corners on different tracks that terrify me while driving a DTM car. If you're bored you can sit and wait and you're guaranteed to see loads of people spin out; one of the most 'popular' crash sites is exiting the Dunlop Curve at the Nurburgring - the seemingly benign kerbing on the left is a death trap. The left-hander after the hairpin at Hockenheim....the kerbing on the final turn at Zandvoort....all these places give me nightmares. So what is it about the DTM cars that cause them to spin out where other classes of car don't seem affected?
Softening the rear bump/rebound can help with stability on kerbs as can softening the rear suspension but both may require a bit of fiddling to find a compromise. I run modern DTM's as soft as I can all round but still close my eyes on certain turns, at certain tracks, thought that was all part of DTM racing!!
Try softening the front and rear springs a couple clicks each. I like to run very stiff springs, but on certain tracks I've gotta go softer for this very same reason (car darts when I take a lot of curb).