Excel 2007 formula returning zero instead of correct result

Hi all,

see attached example worksheet containing two simple active sheets "ANALYSIS" and "PRICES"

The PRICES sheet has a simple sum function in cell f2 that sums pre-determined rates set in column b. This works perfectly as required - enter the check-in date, check-out date and the yellow cell calculates and indicates the price.

The "ANALYSIS" sheet simply references the price info on the "PRICES" sheet with the same formula - the logical function test indicates the correct result, but the incorrect value of zero is returned.

The sheets work perfectly in excel 2000 but not in excel 2007. What could be going on?

Thanks in advance for any clues.