Garry and Martin,

Think I figured it out, although I'm not sure if this is performing as
designed or whether it's an Excel bug.

The macro in question fills a formula in A1 to CV10000 and then saves
the worksheet.

When the macro runs again, it changes a function name in A1 and again
fills A1 to CV10000.

Excel's ever increasing VM Size appears to be related to the fill
process.

Filling over cells appears to abandon the data paged to VM.

However, if I configure the macro to first select all cells except A1
and clear their contents, much of the paged data is recovered from VM.

Does this make sense ?



- Ronald K.