SS501's OST theme for KPN "I'm Stupid" won Song of the Month in the Cyworld Digi Song Awards. They have sold 110,000 digital copies of their song, showing the popularity of the song.
I prefer Hyun Joong's version of it though, I think it's the Ji Hoo effect. ^^
Others have also mentioned that the boys were expressing their disappointment in Hyun Joong for not thanking them and such at the awards. One thing to remember is, the boys said it in good humor, they were merely teasing Hyun Joong. If there's one thing about them, they remind me of Shinhwa in camaraderie. And full blown teasing at every opportunity they get is part of this camaraderie. Why? Because they are the only ones who can do it and get away with it. Because they are brothers. So don't fret guys, it's all for laughs, therefore, laugh with them!
*Credits: Newsen, Daum, Starnews*