Data Bars (pic)

Hey all -- I'm having a weird problem with my data bars in Excel 2010.. The bars do not completely fill the cell at 100% value, and the cell does not completely empty with a zero value.

So for the top one, 8 is 100%, and all the 0s should be 0% (a 4 fills the bar halfway). The cells with 0s should be completely empty, but it seems there's a good 10% of fill I can't seem to get rid of (shortest bar value is set at 0)

Any ideas?