Word 2007 Tables

I'm trying to create a fill-in form that includes a table that can calculate the extended price from the qty. cell and the unit price cell. I have assigned both the qty cell (bookmark Q1) and the unit price cell (bookmark UP1) to be type number in the text form field option box and the extended price cell assigned as type calculation. My expression in the extended price cell box is =(Q1*UP1). My question is: with no values in cell Q1 and UP1, my extended price cell displays, "$1t.00" without quotes. Why is there any value at all? I guess I could understand $0.00 but WTH is a lower case T doing in there? What am I doing wrong? :4-dontkno