Vines lead singer Craig Nicholls revealed today (Nov. 19) that he has Asperger Syndrome, a neurobiologcal disorder that causes autistic-like episodes and severe communication difficulties. The admission was made during a court appearance in Sydney, where Nicholls was facing assault charges stemming from a May incident in which he allegedly kicked a photographer. The charges were ultimately dismissed.

Nicholls' penchant for unpredictable behavior has been a defining aspect of the Vines since the group's 2002 Capitol debut, "Highly Evolved." But the issue apparently came to a head this summer, forcing the band to pull out of its planned support slot on Incubus' North American tour.

Nicholls' unreliability crippled the fortunes of the Vines' sophomore album, "Winning Days," which debuted in April at No. 23 on The Billboard 200 but has sold just 158,000 copies in the United States, according to Nielsen SoundScan. "Highly Evolved" has moved 671,000 to date.

Sources confirm to Billboard.com that the band has not broken up and has not been dropped by Capitol. The Vines are planning to return to the recording studio in the near future, but going forward, it's unlikely Nicholls will be able to commit to extensive concert tours or promotional appearances.