Certainly, there are differences. Both Houston and Brown were once-immensely popular hit-makers, while Sid Vicious was the Sex Pistols' snarling bassist who never learned to play the bass, and Nancy Spungen was a groupie whose dubious claim to fame was being Sid's girlfriend. Still, one has to flip back a quarter-century to find a couple as comparably hellbent as Houston and Brown in their public self-destruction. We already know how the movie ended for Sid and Nancy. In 1979, he died of a heroin overdose while out on bail for stabbing Nancy to death. Both junkies whose nihilistic attachment to one another helped seal their fates, few expected Sid, 21, or Nancy, 20, to die of old age.

At this point, both Whitney Houston and Bobby Brown remain with us. Still, to crib a line Sid's former bandmate John Lydon (Johnny Rotten) once uttered about Nancy, one can't help but see the couple as the Titanic looking for an iceberg.

In the past few weeks, Houston, long rumored to have substance abuse problems, checked herself into a drug rehabilitation facility, only to leave after less than a week. According to her spokeswoman, she's now living in a rented house, but is still participating in a recovery program. Brown, who seems to be on the Prison 2004 tour, was released from a Georgia jail, where he was serving a 60-day sentence for a probation violation stemming from a drunk-driving charge, to face a Massachusetts family court judge after the mother of two of his children claimed he owned more than $63,000 in back child support.

Brown then spent a night at the Norfolk County House of Correction. The next day, he (or somebody) made good on the money, and Brown was released.

An on-going reality show, Houston and Brown have been a convenient punchline for so many for so long -- and I certainly include myself among the smirking masses -- that some may overlook the fact the couple has turned into a joke that simply isn't funny anymore. At this point, they're better known for their antics than their artistry.

Where once there was music, there is now only chaos. Houston, one of the best-selling female singers in pop music history, a woman blessed with an extraordinary voice, has squandered the past half-decade with erratic behavior, ill-advised interviews (put her 2002 conversation with ABC's Diane Sawyer at the top of that list) and numerous performance no-shows. Most notably, she was fired from the 2000 Academy Awards after experiencing various problems in rehearsal.

Brown is even worse. He hasn't had a hit since the early 1990s and was a teary, pitiful figure last week as his lawyer explained in court that Brown has no income or assets of his own, and that his career has "been nowhere near" the heights it once reached. According to Brown's attorney, Houston's company, Whitney Inc., had been making Brown's child support payments until last May.

So what now? How long before Brown gets arrested and locked up again? How long before Houston's drug problems force her back into a formal rehab facility? And will it make any difference for either one of them?

Married for nearly 12 years, it's hard to deny that there must be a very real bond that keeps these two together. Still, they seem too combustible a mixture to ever get the help they both so clearly need. Perhaps if they truly love each other, they'll realize that they're better off without each other -- not to mention for their daughter, Bobbi Christina.

Whether Brown can have any semblence of a career again is debatable. It's been an awfully long time since he was the king of New Jack Swing with "My Prerogative," "Don't Be Cruel," and "Every Little Step," and he hasn't shown as much inclination toward reviving his career as he has for running afoul of the law in various states.

It should be easier for Houston. She's only 40, and still has (we hope) those kissed-by-the-gods pipes. If she can get clean and stay clean, she'll deserve a triumphant comeback. The public enjoys a career resurrection as much as they lap up a public downfall, and it is easy to imagine Houston making a weepy appearance on "Oprah," asking her fans' forgiveness, then chasing all the clouds away with an ear-shedding, powerhouse ballad.

That is, if Houston really wants to sort herself out. With so much unraveling, it seems as if these next few months will be crucial to both their lives and careers. If these past few calamitous weeks haven't served as a piercing wake-up call for this couple, then they'll only continue to fail and fall, as they look for -- and inevitably find -- their next iceberg.

Life in the Pop Lane runs Tuesdays. Renee Graham can be reached at graham@globe.com.