Skimmers are funny things. Sometimes if you feed, dose - (in your case probably the amquel +), or do anything out of the ordinary some/most skimmers will overflow.
I would suggest doing a water change and then turning the skimmer back on.
If you have the money, i'd ditch the seaclown and buy a coralife super skimmer 125 (needlewheel). There's a big thread on it with lots of pictures/feed back and the overall general consensus is it can't be beat for the price and is much better than prizm or seaclown skimmers.
Stewie