Perez & Shar in "Celebrity Rap Superstar" Drama!

UPDATE: Perez finally called us back and tells us that MTV has agreed to go LIVE next week! "When people tune in to the show next week they will (hopefully) see what really happened on the last episode," he says. "MTV has assured me that starting with this coming Thursday's airing, Celebrity Rap Superstar is going to be 100% live and real, as it should be! This will be super exciting. ANYTHING can happen. Shar and I have hugged it out. And DaBrat and me are cool too!"

According to our spies, Gossip Gangstar Perez Hilton was spittin' his rhyme during a taping of MTV's "Celebrity Rap Superstar,"when the sound on his mic went out (check one-two!). Our sources say Perez kept rapping, but the producers stopped him and told him he could start over because of technical difficulties. Perez finished the song ... and walked off stage.

Shar Jackson was up next. Sources tell us she started just fine, then fumbled her rap, forgetting the lyrics. Rather than letting her fumble her way through, producers allowed her to stop and restart her performance -- possibly changing the competition! We're told Perez lost it and rushed the stage, hollerin' that it wasn't right to let Shar re-do her song!

Then, it got crazazy!

Perez stormed off the set to his trailer. We're told that he told producers that the show was now phony, and refused to go on next week unless the show was live! We're told producers also let "Laguna Beach" star Jason Wahler start over, after he effed up his lyrics, which sent Perez into a tailspin. The drama!

For their part, MTV says. "We had technical mishaps early on -- which allowed the first two contestants to "re-start." So, to be fair, every contestant was given the option of performing twice. We wanted nothing more than to make this competition as fair for the contestants as possible."