pasting code in source mode inside ckeditor , style attribute dissapears

im trying to paste regular html code to a ckeditor when its in source mode everyting is ok there except elements like this <img style="padding-top:4px;" src="arrow.gif" />

turns into:

<img style="" src="arrow.gif" />

what gives?... and where can i cha开发者_运维问答nge it?

thanks