Help with rotating banner placement and sizing.

[DeeperImage]

I have it in the right spot, but only the flash banners work fine(retains 468x60 size), the regualar picture banners distort my image header. How can I fix this?? Please take a look at the images below so that you can see what I mean. I also use Power Banner which is simply to use.

Right now I have this code in phpinclude_start
ob_start();
require("/***********/banner.php");
$banners = ob_get_contents();
ob_end_clean();

and then I simply add $banners into any template and it works(shows the rotating banners). If I just add the $banners in the header it messes everything up and does not align on non flash banners only. What html/code do I insert so that it maintains the 468x60 size and shows the banners? and it does not messes up my header image? thanks. The first image is the flash banner retaining the 468x60, the second picture is the one messing up(non-flash banners) I just need to know how to tell it to always be 468x60 regardless and not mess up the header image. Thank you. Someone please help me.