Excel 2000: Linked cells w/diff values

Has anyone seen a problem where in a workbook you have the following situation:

Cell A is referenced by Cell B which is referenced by Cell C.

Cell’s A and B have the same value but Cell C has a different value.

This is part of a financial model and iteration is used. When the iteration is set to an even number A and B have a value of 29.5 and C has a value of 30.8

With the iteration set to 101 the value of A and B is 30.8 and C is 29.5. It looks like C is off by one calcuation.
Thanx
Cell