In the Calculation Options, ensure that Iteration is enabled and set
to the appropriate value (probably 1).

Cordially,
Chip Pearson
Microsoft Most Valuable Professional
Excel Product Group, 1998 - 2009
Pearson Software Consulting, LLC
www.cpearson.com
(email on web site)

On Sat, 12 Sep 2009 09:12:47 -0700 (PDT), wrote:

I've got a workbook with some formulae with (deliberate) circular
references in them. They've suddenly stopped working. Is there
anything the user might have done to make this happen?