Should have ability to right click to accept autosum, not Enter.
 

We can add the Autosum function to a cell with a single mouse click, and
select a range with click and drag. We should also be able to accept the
range and receive a total with a mouse click, rather than having to move to
the keyboard to press Enter.

----------------
This post is a suggestion for Microsoft, and Microsoft responds to the
suggestions with the most votes. To vote for this suggestion, click the "I
Agree" button in the message pane. If you do not see the button, follow this
link to open the suggestion in the Microsoft Web-based Newsreader and then
click "I Agree" in the message pane.

http://www.microsoft.com/office/comm...et.f unctions