It's a video from the annals of TMZ history -- a young and nubile Kim Kardashian walking arm-in-arm with Paris Hilton into Hyde nightclub in 2006 ... breezing straight past Tara Reid, who'd been forced to wait in line.
But last night in Cannes (on Diddy's yacht) -- we're told Kim actually acknowledged Tara's existence, even speaking to the "American Pie" actress for several full minutes.
And to bring it all full circle -- Paris Hilton was there too!!! But we're told Kim didn't spend much time with her.
So we gotta ask ...