Craig, I'm not sure why you say Excel is inconsistant in its results.
The MOD of your example IS greater than zero
(0.0000000000000000216840434497101).
ANY value of which .0005 is not a factor WILL have a MOD0.

So, to answer your question, this is not an error. To avoid this
outcome and if you only want accuracy to 4 decimal places, try your
formula as such:


Code:
--------------------
=IF(MOD(C3,0.0005)0.0001,TRUE(),FALSE())
--------------------


or similar (using ROUND as you did accomplishes the same thing).

HTH

Bruce


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swatsp0p


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