Solver works fine in one of my VBA programs on my PC which has Excel 2003,
but a co-worker who uses the same program has encountered a problem. His
problem started when he switched from Excel 2003 to Excel 2007, and then
switched back to Excel 2003 when macros that used to work in Excel 2003
wouldn't function in Excel 2007. Now Solver, which used to work fine on his
first installation of Excel 2003, will not work with VBA. I thought that
maybe his Solver references had become all screwed up by all this switching
back and forth, so we tried to make sure that the Solver references were
right, and they seem to be.

Any ideas?