I have a workbook with 4 worksheets. The first sheet runs two solvers via
Macros. The second and third sheets have some cells which require user input
and the fourth sheet has a name defined range which the other two sheets use
vlookups to complete all the values on sheet one to run the solver.
Everything works normally so far.

I'm trying to make a userform with 4 tabs that the end user will enter all
of their data into and click solve at the bottom to run the two solvers. On
the userform I'm using a private onchange event with a .cell(row,col).value
=dlgUserInput.Form1Value.Value to update the excel sheets. When I click Solve
I get a "Solver: Unexpected error or out of memory" error. I'm running Office
2003 on XP with 512MB RAM and 1GB Free HD. The solver uses the exact same
code that never fails on my first version of this.