Inserting rows duplicates command button

[Mark Hanford]

I have a UDF that amongst other things inserts 2 new rows a little way above
where a command button sits.

After the user has clicked on the button and the rows have been inserted, I
end up with two buttons drawn on screen - the top one is the original, and
doesn't respond to clicks, the lower is the right one after it's been moved
down 2 rows.

Moving to a different worksheet and back clears the problem. Just moving
the scrollbars clears the problem. It seems to be a screen-draw problem,
but I can't work out how to refresh the view from VBA.

thanks,

Mark Hanford