Invient Charts Date-Axis Problem

Hello Everyone

First off: I really like this addon - its very cool! At the moment I'm trying to do my own "Master Detail Chart" from the demo page, but I stumbled over some very strange behaviour:
When the table contains 'a lot' of data, the labels on the x-axis change their type from Date to Integer. Here an example:

I use the following little loop to generate some test data:

final Date startDate = new Date(2000,1,1);
final Date endDate = new Date(2007,1,1);
		
Calendar start = Calendar.getInstance();
start.setTime(startDate);
Calendar end = Calendar.getInstance();
end.setTime(endDate);
Random r = new Random();

for (; !start.after(end); start.add(Calendar.DATE, 1)) {
    Date current = start.getTime();
    data.add(new Tuple<Date, Double>(current, r.nextDouble()));
}

when I use these start and end dates (-> 7 years) everything works perfectly fine and I get the following output --> check attachment (normal)
but when more data should be displayed (endDate is now new Date(2010,10,1);) something goes wrong --> check attachment (error)
The x-Axis suddenly displays numbers instead of dates (the last two digits seem to correspond to the year...).

The rest of the code is basically the same as the demo. Does anyone have an idea what could be going on here? - Or is it just a bug?

Hope someone has a good answer! - Thanks in advance!