I just finished developing LatestMembers 2.0 on vanilla Ossn 5.0 with Goblue theme. And don't have any issues like that.
Most likely you're running a customized theme and/or component. Effects like that may be caused from malformed html (e.g. unclosed divs) in the HtmlSidebar component, too.
I'd suggest to disable all 3rd party components, make sure you're running default Goblue, then re- enable components step by step and see what happens.