This is a strange behavior and it happens in Chrome and FF.
When I preview by project (build in webserver on localhost) everything is fine and looks like that:
<img src="http://quak.laurig.de/preview.PNG" border="0" />
After exporting it to HTML5 and uploading it to my webserver it turns out like this:
<img src="http://quak.laurig.de/online.PNG" border="0" />