Can"t go to previous year and begindate is wrong Created May 12, 2010

I have a calendar setup like this:

var begdat = new Date(1980,1,1);
var mindat = new Date(1940,1,1);
var maxdat = new Date(1992,1,1);
$(":date").dateinput({value: begdat, max: maxdat, min: mindat, lang:'nl',selectors:false});

bug 1: Somehow the calendar begins on 20th of february in 2010
(i could do $(":date").data("dateinput").addYear(-100) to set it correct)

bug 2: I can select previous month (january) but can't go to the previous year, if i do $(":date").data("dateinput").addYear(-100) and are in the correct 'range' i still can't go to the previous year (only next months and after 10 clicks, next year works ).

When trying to get into the previous year i get this:
TypeError: Result of expression 'i.getYear' [undefined] is not a function. [jquery.tools.min.js:84]

ps: its the 1.2.1 version http://cdn.jquerytools.org/1.2.1/all/jquery.tools.min.js)