We have a portal Full Page IView that hosts a BW Web Application generated by the Web Application Designer. The Web Application fits exactly in the default content pane.
When someone does just a mouseover on the "Reduce/Enlarge Navigation Panel" control, the content window resizes just the smallest amount which changes the flow of my web items that were positioned using CSS.
Our Dev team says that a mouseover on the nav control shouldn't cause any kind of resize of the nav pane or content pane. They think it might be an event generated by the web application that is somehow being caught and causing the resizing to take place. If so then this is some kind of BW Web Application and Portals Integration issue that maybe SAP needs to look at?