I would seriously consider unboxing the content in the left column, or at least re-boxing so that the headings are more clearly connected to the content they relate to. Right now, for instance, the "latest added hosts" heading box looks like one entry, while the actual list of hosts looks like a separate entry. If you remove the border around either one of thos, the connection between the two will become much clearer and more intuitive -- that fraction of a second that the user has to think is, believe it or not, too much for a lot of folks.