[dune-pdelab] Exploding values

[conf86 at web.de]

Hello,

It's me again.

I've finished the code for a model calculation of the 2D instationary heat equation. The intial and boundary values look fine, I also did a printf() of the time component of the source term to see wether it is correct, I also had someone (who does not use dune) check if all the terms and parameters are correct and in compatible physical units – everything is ok.
However, the values are "exploding", i.e. the temperature rises up to something like 1e20 which does not make any sense physically. 
I don't see any numerical difficulties where you could expect strange behaviour, the true solution is actually smooth and so is the calculated one without any diverging parts or oscillations except for the enormously large values, the domain is convex with smooth boundary, etc.
Now, I have no idea what could be wrong, if there's something wrong in the code or something else and I guess it will be quite difficult to say anything without the code and the outline of the problem.
So, I would really appreciate it to find someone who likes to help me finding what is wrong together.

Thank you in advance!

Best regards