Here's what happens in Excel 2003, SP1:

I change a value in a cell (say Sheet1!A1). Another cell (Sheet2!A1,
for instance) fails to update the result of its formula, for example:
=Sheet1!A1.

One curiosity shared by all the above threads is that selecting the
cell (Sheet2!A1), clicking in the formula bar, and pressing enter will
update the cell properly.

Here are the conditions that cause the problem:

Large, multi-sheet workbook
References to cells across sheets
Many lookup functions across sheets (which may or may not be directly
involved in the recalc error)

I am resigned to thinking that I've run into an unfixable problem. I
would like, however, to know why it occurs, if anyone else has run into
it, and why there is such precious little information on the topic.
This little issue has rendered an otherwise well-designed, efficient,
user-friendly sheet error-prone and worst of all, debuggable only by me
because the issue is so sparsely documented.

Here's a link to my old thread. The solution suggested doesn't seem to
help.

http://www.excelforum.com/showthread...hreadid=537288

I've found similar threads:

http://groups.google.com/group/micro...2778dc025e8327

http://groups.google.com/group/micro...a483967e533831