Placebo, Brixton Academy, London, **

Seven years and squillions of column inches of critical opprobrium on, it's easy to forget that Placebo seemed like a good idea in 1996. After all, the frisky threesome's preening pop-punk was a better bet than Oasis and their bloke-ish acolytes. The helium-toned Brian Molko's gender-bending, hedonistic lyrical palette may have been thin, but his band's combination of pre-Nirvana-style US alt.rock (Girls Against Boys, Sonic Youth, Throwing Muses) and feline pop had the edge on an otherwise prevalent retro-Brit parochialism.

They soon lost the momentum, though, Molko cutting an increasingly silly figure. His "oo-er, missus" lyrics regressed, seeming to be culled from The Noddy Guide to Naughtiness ("a friend with breasts and all the rest", from the cumbersome "Pure Morning", still chafes), and he took his second-hand thrill-seeker-cum-tragic diva pose far too seriously. When he wasn't whingeing about being a misunderstood artist, he was trading on faux-controversial drugs references in numbers such as "Special K", a song with all the potency of a paean to breakfast cereal.

Still, this large-ish tour is close to sold out, so Placebo seem to have achieved critical immunity. They kick off with slick, critic-shafting fervour, too, Molko's guitar coiling itself around the lanky Stefan Olsdal's bass on "Allergic" and the colt-ish "Every You, Every Me" to momentarily thrilling effect. The propulsive pummel and thrust is enough to distract you from the lyrics, and the Placebo die-hards indulge in a bit of (albeit desultory) crowd-surfing.

But, like their career in microcosm, the rot sets in fast. When Molko starts crooning-cum-whining through the dirges on his new album, Sleeping with Ghosts, it all becomes soporific, and not only because he's as thin on frontman charisma as he's reported to be up top. "The Bitter End" is nippy enough, but most of the album trades in drearily self-satisfied solipsism, alied to squelchy, Eighties-style keyboards that, Molko probably mistakes for progress. When he moans that "English summer rain seems to last forever" on "English Summer Rain", it's a moot point what he's on about. A soggy July? His song? Spot the difference.

They save the best till encore time, but even then they blow it, slowing down the fizzy rush of "Teenage Angst" to a torpid torch song. For all their early promise of ambiguous, punk-pop mischief, Placebo have become grindingly obvious and earnest. At the end of "Special K", Molko says "No to war!", and looks like he's just reinvented the wheel.

There's the ghost of a good band here, but until it wakes up, say no to Placebo.