So if you only have 9 series no error but if you add a 10th then you get an error? Kind of an odd one. Development has moved on to Sencha Touch 2.1 where the charts are included so any bug in the Touch Charts for ST1 will not be fixed.
I feel the error was basically with the color code or style to be used.
If you see in bar chart if i have more than nine bars it works , but only thing is after the ninth bar the color of the bar starts repeating again which is kind of confusing. So no unique color for each item.