Formula's previously working now resulting in 0? TRIMMEAN + AVERAGE FORMULAS used

Hey Guys,
I'm currently using a spreadsheet to tell me how much of each product to make from Historical data. The formula's that are in there HAVE BEEN WORKING in the past but no longer are. A quick break down of the formulas are;

1. "Pre-Makes" Sheet- Row 5 calculates the "TRIMMEAN" of the last 5 weeks for each column. This line of formula's is no longer functioning???

2. "Dough Production" Sheet- Row 4 (is a bit more tricky) it calculates the "AVERAGE" of the last 3 weeks of data for each COLUMN, PLUS the "AVERAGE" of the last 3 weeks worth of data for the next day (i.e. 4 columns to the right).

As I said, these formula's have been working great until this week. I used Mac08 to build these but now using Windows07 to work them. That was the only change. It's as if the formulas have stopped function, pressing ENTER on each formula returns a 0 result!!!

If anyone can help me out, whether I am doing something wrong or perhaps you can rewrite the formula better, please help!

Regards,
Regan

I checked on my Mac, things seem to work fine. Just checked on Windows Excel 07, "Dough Production" sheet, Row 4 is not working? Perhaps I have some setting turned off? Anything else that I could be doing wrong?