Combo Box not working w/ Sumif even though it works fine in the spreadsheet

The combo box has "2006" as the destination and the source is the cells containing "2003 2004 2005".

This works fine when using a vlookup, but when I replace the vlookup with SUMIF and I add couple lines of additional rows, the SUMIF shows the right calculation, but the chart shows zeros. Is there a trick to this? This is driving me nuts.

Thanks.

e.g.,

Lookup Information

Year 2006 BIKE

Sales Row =+SUMIF($A$6:$E$10,$B$2,B6:B10)

Data

Year Bikes Accessories Helmets Gloves

2003 $234,500.00 $50,403.00 $20,009.00 $30,200.00

2004 $50,002.00 $470,020.00 $2,030.00 $2,030.00

2005 $239,020.00 $100,920.00 $10,928.00 $20,902.00

2006 $400,290.00 $342,000.00 $5,060.00 $9,022.00

2004 $5,002.00 $70,020.00 $2,00.00 $2,00.00

2003 $24,500.00 $5,403.00 $2,009.00 $3,200.00