Why, oh Why does it show me the formula instead of result

I am entering a simple formula =MIN(range) and it shows me the result. I make any edit (e.g., add $ so that I can copy the formula acros without rows changing), hit return, and it shows me the formula instead of the result. Now anytime I type a formula in that cell, it shows me the formula not the result.

What setting do I need to change?

This is Excel Umpty nine, I mean (hold on Microsoft office button, resources, about) Excel 2007.

Thank you.

Update:

This only happens when the range I am referencing (in this case, looking for the minumum value) contains some cells that have text values (in this case, eg. <25 ). If the range I am referencing in the MIN statement has all numerical values (in this case, the results of formulas) I do not have the problem stated above.