This article seems to be on point:

http://support.microsoft.com/kb/243495

--
Jim
"will" wrote in message
...
| Hi,
|
| I have a large (3Mb) spreadsheet with lots of external links.
|
| Calculation is switched to Automatic within Options, yet "Calculate" still
| appears at the bottom of the screen. Is this because there are too many
links
| or its taking too long to update? The "Calculate" does not disappear after
| time, which rather knocks that latter idea on the head!
|
| Any ideas? Anything I should be worried about (eg circular reference)?
|
| Thanks,
|
| Will