According to Twitter reports from Brooklyn rapper Fabolous, auto-tune impresario T-Pain dissed Jay-Z during his performance at Rehab in Vegas Sunday. "Yo I'm at Rehab in Vegas.. T-Pain is DJ'ing.. Sayin F--- JayZ, he old, blah blah.. guess its backlash from 'D.O.A.'" Fab tweeted from poolside at the event.

The party took place at the Hard Rock Pool, where Fab continued to update his followers on the day's events, tweeting "So I'm here wit Rihanna, @richyungamerica, & @paulcainsf.. Drinkin some strawberry/daquiri's.. Not feelin the Tpain JayZ dissing.. Brooklyn!"

Jay has notoriously called for the 'Death of Auto Tune,' but stated that he meant no offense to artists like T-Pain, Kanye and Lil Wayne, who use the software "artistically."

T-Pain responded by crashing Jay's June performance at Summer Jam, standing by Hova as a "show of support," while he performed his anti auto-tune anthem, despite the fact that the Brooklyn MC was calling for the death of Pain's sound. Now it seems that T-Pain is revealing his true colors. Though footage of his diss hasn't appeared yet, the DJ's at Rehab followed up his announcement with an all Jay-Z set, started off with D.O.A..

"Yo the DJ is doin a jayz set.. D.O.A., kingdom come, run this town, heart of the city, h to the izzo, amillie free.. Tpain somewhere in here," Fab reported.

Looks like the people side with Jay, Pain. Sorry.