Lindsay Lohan is in hot water again.

At a hearing in Beverly Hills Friday, a judge slapped an extra year on Lohan's existing three-year probation sentence.

Lohan, looking solemn and appearing gaunt, wore a white sportcoat, black pants and her hair in a bun as she walked into the courtroom holding her attorney's hand for a progress review in her two DUI cases.

Her attorney Shawn Chapman Holley explained to the judge that a miscommunication had occurred when Lohan failed to notify instructors of an alcohol education class she attends as part of her probation that she would be returning to the class after she left the country for work.

Judge Revel sternly warned the actress, "I ordered you into court today because I wanted to speak to you directly. I don't want to get any more notices again [that you might be in violation of probation], no warrants ... where you're thumbing your nose at the court."

Judge Revel ordered Lohan to get prior court approval the next time she leaves Los Angeles for work, and warned that any failure to comply with the terms of her probation could lead to jail time.

But the judge also voiced a conciliatory tone when she told the troubled actress, "I'm rooting for you to successfully complete probation."

Lohan's only words in court were "yes" when asked if she understood all the proceedings. A progress review hearing was set for Dec. 15.

Lohan was sentenced to the probation term following her second DUI conviction in August 2007.

Earlier this year, the court issued an arrest warrant for Lohan, also related to her class enrollment, but the matter was later determined to be a misunderstanding and was dismissed.