Crystal Reports Formula not working

Message

   Hi All,

My report lists open orders for our company, and from which locations our product is in for that order.  Said report uses the following formula:

if {IC65A Quantity by Location.Location code}= "  4" then
    {IC65A Quantity by Location.Qty on hand}
        else
            0

Basically all this does is tell the report to show the qty on hand we have for location 4.

The funny thing is that I can get this formula to pull the correct data in a sample report, but not in my more complex open order report.

I've made sure that all the linking is the same (through the visual linking expert), I'm using the exact same databases, and there is nothing in the selection expert that tells the report to exclude certain locations or items.

The really weird thing is that I get the correct data for some items, but not for others.

Can anybody think of any reason why the formula would work in one report but not the other?

Thanks!