With songs like "Fat Lip" and "Motivation," Sum 41 developed a reputation for cheekiness and tomfoolery. Their new album doesn't exactly transform them into tree-hugging environmentalists or pulpit-preaching activists, but it shows the bandmembers leaning toward maybe growing up just a little ... kinda.

Many songs on Does This Look Infected?, due November 26, aren't about downing brews, scamming chicks or teenage angst. Instead, Sum 41 singer and lyricist Deryck Whibley addresses issues a little more sobering.

"I guess I watched too much CNN while making this record," he said. "Also, I guess I'm getting older. When you're young you have an excuse to be stupid, but as you grow up it's good to learn about everything that's going on."

"Still Waiting," the first single on Does This Look Infected?, addresses political turmoil in a way reminiscent of many '70s punk bands. "So am I still waiting for this world to stop hating?/ Can't find a good reason, can't find hope to believe in," Whibley sings on the song's chorus.

"I don't know, man," he said. "It just seems to be one of those things that I don't think will get better. And if it does get better, it's going to get a lot worse first. I'm not blaming anybody or putting anybody at fault or saying who's better or worse. I think overall it's hard for everyone, but I don't think it will ever get resolved."

Musically, the song is more metallic than most of the tracks on last year's All Killer, No Filler, but punk-pop fans will be pleased to know that — regardless of the group's affinity for Iron Maiden — the song is a far cry from "Number of the Beast."

The tune starts with a punchy serrated rhythm and incisive guitar riff, then shifts into a shouted verse reminiscent of the Offspring. But by the chorus Sum 41 have hit a melodic groove filled by churning guitars and an infectious vocal hook.

"We've always liked mixing styles," Whibley said. "We did it with 'Fat Lip' or some of our other songs where we were trying to do hip-hop and punk rock. [This time] we just wanted to do metal and melodic rock. It's my favorite song on the record."

A video for the song was shot last week by Mark Klasfeld, who worked with the band on their "In Too Deep" and "Fat Lip" videos. Like "Fat Lip," it depicts the band acting up and rocking out without a script or a safety net.

"We're kind of the anti-treatment band," Whibley said. "We just show up and tape a bunch of stuff and see what happens. That style worked so well for us when we did our first video, for 'Fat Lip,' that we decided we should do that all the time. It's so off-the-cuff it ends up being better."

In addition to jokingly mugging for the camera and sporting punk poses, Sum 41 spoof the current crop of "it" bands, including the Hives, the Strokes, the Vines and the White Stripes.

"When it comes down to it, we just like having a laugh," Whibley said. "To us, nothing's sacred."

For a full-length feature on Sum 41, check out "Sum 41: Testing Their Metal."