I solved the problem. After looking more carefully at the examples, I
replaced my code with this one:
$("#myArrow").rotate({
bind:
{
click : function() {
if ($('#myDiv').is(":hidden")) {
$(this).rotate({animateTo:0});
$('#myDiv').slideDown("slow");
} else {
$(this).rotate({animateTo:-90});
$('#myDiv').slideUp("slow");
}
}
}
});
Now it works perfectly on Firefox, IE and Chrome :)