Vlookup Returns #N/A in XCelsius

I just acquired XCelsius 2008 and have run into an issue that I am hoping someone can help with. I am building a model and am finding that when I use a Vlookup of a table of data, the data is found and displays correctly in the Excel window of XCelsius and also in the display window of XCelsius. However, when I run a Preview in Flash the data in the Vlookup area shows as #N/A.

I really need the Vlookup option to work as I have a number of items to lookup which would exceed the nested IF function. Can someone point me in the right direction please...?

Thanks, David