Hi,
It's been a while since I worked with Excel Solver.. I used to have the
same problem.

I think that you have to Reference to the Solver Library first:
Tools References, and check the reference for Solver.

I you have already done it, and the debugger still pausing in the
solver code, add a line with at the beggining of your code:

Solver.Reset

Regards

LCK

PD. You can find more information about solver on
http://www.frontsys.com.
Those people developed Solver platform and licensed it to MS.