I got it solved at the SILabs forum

stupid mistake
Thanks Tsuneo
That you 'proved it working' made me triple check which did not help, but a quadruple check (unning with SRC once more) did the trick.

I do not run #pragma SRC for obvious reasons (but ran it once to get the segment name) and what happened was that adding a variable inserted a '_' in the name of the segment. I missed that detail in every check so far, but now it works

Thanx a whole lot

Erik

PS an error message in this case from Keil would have been nice