Robin Thicke, Paula Patton Square Off with Cops ... Again

Robin Thicke and Paula Patton got into it again in their custody war, and cops rushed to the scene again.

We've learned the incident went down Thursday at a Malibu park, where Paula was supposed to hand off 6-year-old Julian to the court-appointed monitor so Robin could have his visit. We're told Robin was also present, but here lies the conflict.

Sources connected with Robin tell TMZ the singer was aware Paula has a restraining order but he never came close to her. The sources say Paula was an hour late and when she arrived she refused to give Julian to the monitor. Our Paula sources say the monitor arrived at 3:13 PM and she arrived exactly on time at 3:30 PM.

Sources connected with Paula say Robin violated the restraining order and was feet from Paula when she arrived with her son. They say Julian decided he didn't want to go with his dad and asked her to call 911.

We're told Paula's people called the cops, who came to the scene but by the time they got there Paula and Julian had left. When the deputies arrived, our Robin sources say the officers told him a black SUV resembling Paula's had gotten in an accident. He freaked out and left to find the SUV.