Harsh:

If you are into derivatives and calculus, you may find the mathematical response to your question here:

http://en.wikipedia.org/wiki/Stability_derivatives

For a not so mathematical approach, listing the many factors involved:

http://en.wikipedia.org/wiki/Dihedral_(aircraft)

I would like to learn how did you arrive to the conclusion that you presented in the forum of reference regarding relation between dihedral and wing span.
It seems to be that it should be a direct relation, instead of inverse.