12-month datepicker and themeroller: broken when click on day

Hello, i'm trying to display and style a 12-month datepicker calendar with jquery-ui-1.8.17. Initially it shows fine, i.e. it shows a complete year in 3 rows, each row contains 4 months. BUT, when i click on a day in the calendar, the display jumps to 1 line containing 12 months! Anyone seeing this strange behaviour also or has a solution?

Note: in my code, i included jquery-ui-1.8.17.custom.css. This is file is generated with http://jqueryui.com/themeroller. See the links in the css file.

I suspect it might has something to do with the css generated with the themeroller.

note: it also happens with 1.8.19

See also http://jsfiddle.net/r7pEe

http://stackoverflow.com/questions/10198379/jqueryui-datepicker-12-months-view-jumps-when-clicked-on-date