integrated zf with ckeditor

hi all, i am using ckeditor in my current zf project, it's so weird, everytime i insert an image, its src looks right via source button, but it's completely changed afterwards.

<img alt="" src="images/special.jpg" />

became to

<img alt="\&quot;\&quot;" src="\&quot;images/special.jpg\&quot;" />

how could i avoid this thing. thanks in advance