I'm not an expert, but I can't see how the Undo feature would have anything
to do with this.
What is your code to define your Selection?

"James McDowell" wrote:

Is there a way to turn off the Undo Feature for a worksheet?
I can not seem to find it in the help.

I have to consolodate 50 columns(12,000 rows each). After I calc I wish to
delete the 50x12,000 matrix by using selection.clearcontents but it does not
clear the entire range selected.

Is my answer trying to turn off UNDO or is there a separarte issue?

Jim