BET Awards

1:00 PM PT -- Mindless Behavior just apologized for the diss, tweeting, "We meant no disrespect to our girl Lauryn Hill last night, it was a bad joke. We're big fans and hope you're not mad!"

Beyonce wasn't laughing when a boy band DISSED Lauryn Hill at last night's BET Awards ... in fact, Bey was so upset, she changed her acceptance speech (on the fly) to HONOR the former Fugee.

So let's start with The Diss -- Comedian Mike Epps and the group Mindless Behavior were co-presenting the award for Best R&B Artist when Mike jokingly tried to sing.

One of the members of the group quipped, "You sing BAD ... like Lauryn Hill's tax accountant bad."

The diss drew gasps from the crowd ... and pissed off Beyonce, who ultimately WON the award that was being presented.

But TMZ has learned ... B was so upset, she scrapped the speech she had prepared and defended Lauryn's honor instead ... saying, "I want to thank all the talented R&B women that came before me like Lauryn Hill and Mary J. Blige."

When B walked off stage, there was a woman waiting for her -- possibly a BET handler -- and B began to vent about the insult, saying the Lauryn Hill diss was "disrespectful" and "not cool."

The woman complimented Beyonce for adding Lauryn Hill's name to her acceptance speech ... to which Beyonce replied, "I just felt [the diss] was wrong."

You might think Chris Brown would be persona non grata at the official BET Awards after party tonight, but TMZ has learned the nightclub combatant was indeed invited and RSVP'd yes.

According to our sources, CB will be in attendance at the star-studded soiree going down at Playhouse in Los Angeles ... where Usher, Common, and Kevin Hart are among the anticipated guests.

We're told Brown's people told party organizers the singer will be showing up and that the invite came AFTER the events that went down at W.i.P. in NYC. In fact, the party tonight is being thrown by people connected to W.i.P.

Heavy D was planning a huge comeback just before his death -- and those plans included a new music video.

Carl Thomas, who sang on Heavy D's latest album, tells TMZ, he was in touch with Heavy two weeks ago ... and Heavy told him he was weeks away from shooting a music video for their song, "Still Missing You." Thomas said Heavy had a director in place and had picked a location for the shoot.

Sources close to Heavy D tell us it was all part of the singer's comeback plan. We're told he released his new album on September 27 because it coincided with the BET Music Awards ... and he was hoping the performance would put him back on the map.

As we first reported, Heavy D passed away on Tuesday after collapsing outside his Beverly Hills home. He was 44.

TMZ obtained the video, which shows Bieber -- who was a presenter at the award show -- and his squad being stopped at the door last weekend. It appears one of Justin's bodyguards did NOT have a ticket ... and while both sides argued, Biebs eventually interrupted by saying, "I need to bring my security! This guy's a douche bag."

Everyone on Team Bieb ended up getting into the show -- and a BET rep downplayed the incident ... saying, "It is our standard policy to make sure everyone has their tickets or credential upon arrival. Justin had the proper credentials."

As for Justin -- his rep says the Biebs was just standing up for his bodyguards ... the guys who always have his back.

Some "lucky" BET viewers were chosen to present the viewer's choice award at the show last night ... but there was a HUGE mistake ... because someone put the wrong name on the teleprompter.

So the lucky fan read the winner as "Chris Brown" ... but quickly recanted and said, "I'm sorry, the winner is Rihanna." But that wasn't the case either ...

Despite the fact that Rihanna's name appeared on the video screen as the winner ... one of the presenters chimed in for a THIRD time and announced Drake as the winner!!! Drake then appeared on stage to collect his trophy.

Drake gave a short speech and described the whole thing as awkward. Understatement.

After the awards, a BET rep announced that Brown was the correct winner -- and chalked the whole thing up to a "human error" on the part of BET producers.

The waterworks start around 4:30 mark if that's what you're into -- but seriously, his dance routine before that was amazing.

He started crying right as he got to the "Man in the Mirror" portion of the medley. Coincidence?

Platinum-selling superstar Robin Thicke has been nominated for two BET Awards: Best Male R&B Artist, and his song "Lost Without You" is up for a Viewer's Choice Award. Only two other white artists have ever even been nominated for a BET Award -- Justin Timberlake and Eminem -- but neither of them took home the prize. Could Robin break down the BET color barrier?!

The competition is thick; Thicke is up against Akon, John Legend, Gerald Levert, and Ne-Yo for Best Male, and competing with Beyonce, Birdman & Lil' Wayne, Bow Wow featuring Chris Brown, Ciara and UNK for the Viewer's Choice.