In case anybody else gets whacked by this problem:
(BTW - anybody know where I can post a bug report?)

Some weeks ago I posted about how awfully slow a model was running in 2007
vs. 2003 when calling the Solver add-in. I have fiddled with the model off
and on since then, being careful to invoke the code that calls solver ONLY
when on a PC with Excel 2003. However, I stumbled across the source of the
problem today - linked pictures.

The worksheet on which solver is run HAD a picture linked to a 4 column by
12 row range on another worksheet. After deleting the picture, a process
that was taking nearly 40 minutes to complete in 2007 ran in just over 30
seconds. That process involved calling solver 10 times.

Oddly, there is only a barely perceptible difference in speed in 2003
between the version that has the linked picture and the version that doesn't.
In 2007, though, the difference in speed is staggering.

Lesson: stay away from the combination of linked pictures and and solver in
2007