After stepping out from behind the shadow of Celine Dion, for whom she was once a back-up singer, R&B vixen Deborah Cox is currently basking in the success of her Top 5 single, "Nobody's Supposed to Be Here."The Canadian singer, who released her self-titled debut back in 1995, has also paid her dues -- and bills -- by singing on various commercials on advertisements, a past she confessed about during a recent interview with MTV News. "I did lots of jingles," she said,"for Bonanza, for car commercials. I did one, the one that actually got me started, was for a company called 'Marvelous Muffins' (laughs) ... It's a Canadian company." [28.8 RealVideo] The former ad girl's new album, "One Wish," features a duet with Next's R.L., as well as some writing and production assistance from Montel Jordan and Kay Gee from Naughty By Nature. Cox plans to launch a tour in support of "One Wish"