Wait, Nick Lachey still has a career? When did that happen? Apparently he and longtime girlfriend Vanessa Minnillo are on the rocks. Now to be fair, she probably doesn’t understand his career issues, because she’s never had one. Unless you count being an MTV veejay (and supposedly an entitled diva) a career. Technically she considers herself an actress (she even plans on winning an Oscar), but frankly she has nothing going for her except being Nick’s girlfriend. And by some reports, that’s going down the tubes too.

A source close to the ex-boybander says the two “are on the rocks big time. They argue all the time, and Nick is done with her. He feels like she’s holding him back, careerwise.” Sure enough, Lachey’s career isn’t as hot as it used to be. His latest single, “Patience,” hasn’t even cracked the pop charts, though a friend close to the singer is quick to note “it’s doing well on the adult contemporary.” (When we checked, it was No. 39 on Billboard’s Hot Adult Top 40 list after five weeks of airplay, and it topped out on the Pop 100 Airplay list at No. 75 back in March.)

… what the singer really needs is a mainstream breakthrough — and Lachey’s pals say that in order to launch a comeback, he needs to dump Minnillo. It was recently reported the end was near after Minnillo stormed out of an L.A. restaurant with an angry face — with Lachey chasing after her in embarrassment, doggy bag in hand. A source close to the couple told us, “After the pictures came out, Nick told friends they weren’t fighting about their relationship, that it was just Vanessa going through a tough time personally.”

But, says another source, “We’re just not sure if we believe that anymore. The relationship has been over for a while, but he’s too nice a guy to end things completely.” That may explain why the singer keeps making an effort. In town for a recent Lachey promotional tour, he and Minnillo — who’ve been together since March 2006 — dined at The Charles restaurant. “They sat in a corner table, exchanging kisses,” said one spy. “But something still wasn’t quite right.”

[From Gatecrasher]

Of course both of their reps denied that anything was wrong, because life is nothing but rainbows shooting out of unicorns’ asses in celebrity rep land. They’ve been together for three years. Lots of couples date that long without getting married, and I’m not saying there’s anything wrong about that. But, it’s long been rumored that Vanessa was eager for Nick to pop the question, and given that, it’s been a long time. If she wanted to get engaged, I’m surprised she hasn’t dumped him after all this time. I think she’s smart enough to know Nick is the only fame she’s got right now.

And while Lachey has always struck me as a reasonably smart guy (at least by celebrity standards), I don’t think Vanessa is the reason for his flagging CD sales. He’s just over. His young hot boyband time came and went – and he was never one of the biggest acts, even when he was on top of his game. Gatecrasher also noted that he’s producing shows for MTV, and that sounds like a smart plan for the long-term. If either of them is considering staying or leaving because of their career, it’s time to call it off.

Here’s Nick Lachey and Vanessa Minnillo at the New Years Eve celebration at Fontainebleau’s LIV nightclub in Miami Beach. Images thanks to WENN.com .