Three years after her brief stint in the slammer, Lindsay Lohan may be headed back behind bars — and Mother Nature may be to blame! According to reports, the troubled starlet, who was convicted of her second DUI in 2007, has failed to follow her judge's orders to attend alcohol education class once every seven days — and she's due back in court on May 20. Too bad Lindsay, who has been spotted partying around Cannes, may not be able to make it because the volcanic ash around Iceland is reportedly preventing her from catching a flight back to LA! The judge accused Lindsay of "thumbing her nose at the court" last October at a Beverly Hills court hearing for skipping her required classes, and added an extra year onto her probation sentence. Now, if she doesn't show up on Thursday, a warrant will be issued for her arrest and she could face jail time. She was locked up for 84 minutes in November 2007 after a tough year of two DUIs and three stints in rehab.