Skimmer overflow...

I have a super skimmer 125. It has been running fine for over a year now. The this morning before work I noticed the floor was wet. I open the door to the sump area and noticed the water level was low. Apparently the skimmer had overflowed and instead of the water draining back into the tank it found its way to the floor. I had cleaned the collection cup two days earlier and check it daily for skimming action. What would cause it to suddenly overflow?

 

Did you add anything to the tank recently? Many times certain additions will cause the skimmer to go "crazy"? Epoxy to glue rocks or corals comes to mind.

 

I did add a new maxi-jet pump and some hose for a phosban reactor. Its been setup for about a week now.