Backgound color modified in Panel stylizer shows strips in IE 7

I think i founded something :
It's appear that the module generate dynamicaly ccs file from your style, default templates can be find here : ....\sites\all\modules\panels\plugins\style_bases\pane\pane_rounded_shadow\pane-rounded-shadow.css

At the beginning of the file you can find this :

.rounded-shadow-top-edge, .rounded-shadow-bottom-edge, .rounded-shadow-left-edge, .rounded-shadow-right-edge, .rounded-shadow-wrap-corner {
position: relative;
/* hasLayout -1 ? For IE only */
zoom: 1;

Just comment the line "zoom: 1;" (line 4) that will make disappear the white lines on top and bottom of pane content.

I had a second bug with IE : i had gradient in the pane content in IE whereas in Firefox i had plain color. In the same file line 16 :

%style .rounded-shadow-background {
margin: 10px;
background: url(rounded-shadow-background.png) repeat;

Replace "url(rounded-shadow-background.png) repeat" by "%background" it will take the background color value that you've selected in your style.

Hope it will help.