owtchart snall numbers

I'm trying to plot some data wit owtchart as Steve suggested me but I'm having 
some problems plotting small numbers. In first place I couldn't find the way 
to make the cgi read scientific notated data, so I had to regenerate my 
shapefiles. Once I got them written in normal notation I found that I 
couldn't plot small numbers as small as  -0.00000000164566937855 is this a 
common limitation? The url I'm sending is:

http://localhost/cgi-bin/owtchart?Type=Line&W=300&H=200&NumSets=1&NumPts=31&Vals=0.00000000000000000000!0.00000000000000000000!0.00000000000000000000!0.00000000000000000000!0.00000000000000000000!-0.00000000164566937855!0.00000000024503654661!-0.00000000007510970318!0.00000000055291687895!0.00000000050531184792!0.00000000002954476941!0.00000000050230053450!0.00000000013284597034!0.00000000040191416861!-0.00000000050866350021!0.00000000020380243326!-0.00000000019812386454!-0.00000000044895726026!0.00000000087982593433!-0.00000000000214305635!0.00000000191609705880!-0.00000000056374438451!0.00000000077850459412!-0.00000000094573238130!-0.00000000024245977448!0.00000000378907261123!0.00000000258610421966!0.00000000457244464513!0.00000000351854634317!0.00000000091475138575!0.00000000040152881020

Thanks, Tomas