Britney Spears' 5 Biggest On-Stage 'Oops'

Britney Spears' "Circus" is chugging along, but not without its fair share of setbacks and slip-ups.

The pop star's first tour in five years has been punctuated with "oops, I did it again" type moments worthy of their own blooper reel. The latest: an overzealous fan stormed the stage and tried to shake it with Spears at her Sunday night show in Connecticut, sending security guards into a frenzy and racking up an arrest.

Video: Britney Spears performs.Play

With the news that Spears is expanding the international leg of her tour beyond Canada and London (where she's reportedly requested a stripper pole in her hotel suite for off-stage workouts) to Sweden, Germany, France and Russia, it seems an appropriate time to assess what mistakes Spears might want to avoid as she greets her global audience.

Below, takes a look at four major mess-ups from Spears' "Circus" tour thus far and as a point of reference, looks back on one of the biggest blunders of the 27-year-old pop star's career.

Spears' Show Goes Up in Smoke

Spears concert-goers play by her rules, and that means no smoking -- or else she stops the show.

The pop star left the stage for half an hour at an April show in Vancouver, Canada, apparently because of smoke in the audience. Spears stopped performing about 15 minutes into her show, and an announcer told fans to put out their cigarettes, some of which may not have been of the tobacco variety.

Upon returning to the stage, Spears scolded the crowd, saying "Don't smoke weed." Following the show, Spears' publicist, Holly Shakoor, issued a statement apologizing to fans about the delay. The statement said "crew members above the stage became ill due to a ventilation issue."

Funny -- Spears didn't seem to mind smoke back in July 2008, when she was publicly slammed for puffing cigarettes in front of her young sons.

Spears' Roadies Make Own Record

Spears is in the business of making records and so, it seems, are some members of her crew, although you won't be hearing their tunes on the radio any time soon.

In March two of Spears' tour roadies setting up for her stop in Pittsburgh ended up with a couple police records for criminal conspiracy, disorderly conduct, public drunkenness, simple assault and resisting arrest.

It all started when Pittsburgh police say they saw Rockey Dickey, a member of Spears' crew, punch a complete stranger in the face. When an officer tried to stop the fight, Dickey allegedly swung at the cop. Officers ended up using a taser to subdue him.

But if that wasn't enough, police say Alex Montes, who also works for Spears, tried to come to his buddy's aid by putting one the arresting officers in a headlock.

Following the incident, Spears quickly put distance between herself and the crew members in a statement released on her web site: "Last night two employees of a company contracted to provide equipment for "The Circus," Starring Britney Spears tour were arrested in Pittsburgh, Pa. However, neither of the men involved are employees of the tour or Ms. Spears. The two individuals have since been dismissed by their employer. "The Circus Starring Britney Spears tour does not support or tolerate this type of behavior."

Spears Lets It All Hang Out

It's a position in which no woman ever wants to find herself. Nipple slips and panty lines are one thing; Spears' latest on-tour wardrobe malfunctions, both involving the region just south of the border that got her in trouble with the paparazzi three years ago, are far and away more embarrassing.

But maybe she begs to differ. At a March show in Tampa, Fl., Spears' leotard ripped, exposing her bare crotch to the audience. Spears waited until after wrapping her performance of "I'm a Slave 4 U" to unabashedly acknowledge the gaffe. While being lowered beneath the stage to change costumes, perhaps not realizing her mic was still on, Spears announced, "My p**** was hanging out," causing the arena to erupt in laughter.

At an Anaheim, Calif. show in April, Spears let something else hang loose: tell-tale evidence of a tampon. The 27-year-old mother of two might want to consider more substantial stage wear to solve these situations.

When Daddy's Away, Spears Will Play

When the cat's away, the mice will play. Or in Spears' case, when her dad Jamie, also her conservator, was away on business in Los Angeles in late March, Spears reportedly had a little fun with one of her backup dancers, a hunky 21-year-old named Gio.

After a few rumored backstage interludes, Spears bought the hoofer "a pair of shoes and some clothes, even though she's on an allowance," a tour insider told the New York Daily News.

But when dad, who's had his daughter on a tight rein since being put in charge of her affairs, returned to the tour, the brief affair cooled.

That could be a good thing. The last backup dancer Spears fell for, Kevin Federline, ended up becoming her husband and the father of her two boys. And we know how that ended up.

Spears' Screw-Up Heard 'Round the World

But nothing compares to Spears' performance at the 2007 MTV Video Music Awards, in which the already scandal-scarred pop star dug herself another six feet under.

Kicking off the show with her latest song, "Gimmie More," Spears appeared to be acting out the classic nightmare of arriving at a party and realizing you're naked while people point and laugh. She seemed to sleepwalk through her routine, flailing her arms and failing to synch her lips with the sub-par dance ditty blasting through the speakers.

Spears' sequined bra/panty costume confirmed that like her former pop-star magnetism, her abs of yore, which she famously adorned with a live snake at the 2001 VMAs, were nothing but a memory. Critics panned Spears for losing the figure that made her a star and trying to shake it in a far too skimpy outfit.

In 2008, Spears attempted to override the previous year's fiasco by once again opening MTV's VMAs. But instead of singing, the network had her perform a skit with actor Jonah Hill and read an introduction off a teleprompter. It seemed like a cop out at the time, but looking at Spears' on-stage mishaps since then, maybe it was the right move after all.

Additional reporting by ABC News' Luchina Fisher.