Why do i lose EOMONTH on file close

[Jake]

In Excel 07 when using the Formula EOMONTH in a workbook, this formual is
completely lost when i close or save the workbook. Any suggestions are
appreciated.

 

[Gary Brown]

re-post with a better description of what you mean by 'completely lost'

 

[Jake]

Waht i mean by lost is the this; the formula is replace with =#N/A