Ajax enabled Web User control are positioned incorrectly in firefox

Could ne1 help me out with the concern of relating to positioning of a
web user control in ajax enabled website.Actually what is happening is
when a put a web user control in an ajax enabled webform to a certain
position on it and try to view it in firefox browser the web user
control automatically comes to left top of the page but if i view it
in IE its workin fine..
Can ne1 let me know the probable reason for the same.
Thanks