No Images relative URLs in Internet Explorer < 9

Hi Guys,

i use FCKEditor in Version "FCKeditorAPI = 'Version : "2.6.4",' 'VersionBuild : "21629". I don't expect any Problems with pictures in IE9, FF or Chrome.
But in IE8 or IE7, i got problems with inserted Pictures with an relative URL. They can't be displayed and in the properties of the image i can see, that there is no host inserted in the media url.

For example the ImageUrl is '/relative_media_url':
IE9/FF/Chrome -> http://localhost:8080/relative_media_url -> correctly displayed
IE7/8 -> http:///relative_media_url -> broken image

I experimented with the Property FCKConfig.BaseHref in the config and changed it like this:
FCKConfig.BaseHref = 'http://localhost:8080/' ;

..but there is no effect, the url is still unchanged (in every browser).

Unfortunately, i am depentet to this relative url and i cannot change it, it has to be the same as before, so i thought the BaseHref Property will solve my problem, am i use it in a wrong way or do i have to adjust another part?

Thanks for your reply, greetings Michael