Lindsay: You Got Served

honoring George Clooney Friday -- a subpoena! And to make matters worse, it all went down on the red carpet.

It all started after the actress was approached by a woman who Lindsay assumed was an autograph seeker on her way out of the event. Lindsay said to the woman "You're my first autograph!" to which the woman promptly answered "You've been served." According to witnesses, Lindsay then dropped the paperwork and chased after the process server. No word on whether she caught up to the process server.

The lawsuit involves Dina Lohan (Lindsay's mother) who is being sued for fraud, theft, and violation of contract. The suit, filed in Las Vegas, claims Mama Lohan signed a contract with Antonio Almeida and Mitchell Chait authorizing them to manage Lindsay's music career and record her album. The suit then claims Dina dumped the two managers and signed her daughter with Tommy Mottola's Casablanca Records, who in turn produced Lindsay's two albums. The suit seeks tens of thousands of dollars for cash the producers say they loaned to the Lohans.

TMZ spoke with Charles Coate, attorney for Almeida and Chait. He told us "[Lindsay] was in fact served in connection to the Vegas complaint. Also, Miss Lohan is only a witness, not a party in the case, and the allegations in the complaint speak for themselves."

A rep for Lindsay could not be reached at press time.