Excel 2007 : Editing Formulas in Excel '07

I've been experiencing a very frustrating issue in Excel lately that I can't put any rhyme or reason to. I'm hoping someone here can help.

We are a sales company and I use Excel to provide production reports from our CMS system.

This requires me to use formulas to calculate different aspects of our sales production.

As we grow, there is a need to go back and edit or change certain formulas. Most of the time, I can just change a number to extend a formula and it is successful in changing. Other times, and for no apparent reason, it changes the formula to text instead of calculating the answer.

Below is an example from today:

I started with this formula and just needed to extend its reach.

=COUNTIF(U5:U83,"baltimore")

So I changed 83 to 125 and it works perfect.

=COUNTIF(U5:U125,"baltimore")


Then I attempted the same with the following:

=COUNTIF(U5:U83,"pioneer")+Y54

When I go to change the 83 to 125 in the above example or anything in the formula for that matter, it changes to text instead of giving me the count. So, literally, when I hit enter I see the formula still written out in that cell instead of a 6 or an 8 in there for the count.

Please, if anyone can provide some rhyme or reason to this so I may avoid the many additional, and seemingly meaningless, steps it takes to resolve this issue, I would be very appreciative.

Thanks!

-Aaron