Weird problem - why are these two files acting differently!?

[andyintel]

Hi,

Hoping somebody can help with this. It's probably really obvious although it has stumped 5 of us at work so far.

Attached are two files : Book 1 and Book 2. What I would like you to do is the following :

Open Book 1
- In cell A1, enter 1234.5678 and press enter
- Go back into A1, and press the 'Decrease Decimal' button twice
- Now press the 'Increase Decimal' button twice
The number you will be left with in cell A1 will be 1234.5700

Now repeat all of the steps in Book 2, exactly the same.

The number you will be left with in Book 2 is 1234.5678.

Please can somebody explain why the two workbooks are behaving differently? And how can I get Book 1 to behave like Book 2?

FYI, Book 1 used to have some confidential data in it, which I had to delete before posting here. I need to keep using Book 1 and cannot just transfer all the data to Book 2. Book 1 also has a macro in it, so it is a .xlsm file rather than .xlsx, but I can't see anything in the macro which has affected how Excel calculates a cell.

Many thanks,
Andy