This is a nuglet worth it's bits. If adding an inline CssCode property to a Chameleon element, remember that the default CSS tag generated is a DIV tag, which means that you'll see line-breaks and not be able to figure out why.
Add a tag="Span" property (in bold below) and you'll be in Community Server CSS bliss once again.
<DBVT:POLineDetailsImageLink ID="POLineDetailsImageLink2" runat="server" CssClass="PopOver" Tag="Span" />