My formulas do not calculate in some Excel applications - help!

[Mike Correll]

I provide an Excel spreadsheet to my field sales team for quoting projects.
It has worked very well for the past few years, but in the last revision I'm
getting calls from sales reps saying that some formulas are not calculating.
It's not as if an error is displayed - the formula simply does not calculate.
Also, it is the same group of formulas each time.

However, when I test the file out on my computer, all formulas calculate. I
cannot recreate the problem on my computer.

Is there a setting in Excel that limits the number of possible calculations?
Any insight that can be provided on why this is happening would be greatly
appreciated. I am truly at my wits end.

 

[Barb Reinhardt]

Are these User Defined Functions or Built in Functions?
Do the users have their machines set to calculate Manually? Tools ->
Options -> Calculate