Supershow Jazz/Blues film from 69?

Has anyone seen the DVD Supershow? It is footage from 1969 that features Eric Clapton, Jack Bruce, Buddy Miles, Buddy Guy, and The Modern Jazz Quartet among others. It is supposed to be a huge jam that took place in an old linoleum factory. I dont know the purpose of the jam session, just that it happened and it looks pretty cool. Anyone know what I am talking about?

 

I've only ever seen clips of this show - there are interesting combinations of musicians. The music isn't commercial at all, so this is very different than the average music film of the time where pop bands lip-sync'd.

Excerpts are often shown in documentaries (VH-1 type shows) and they always share one problem; the video and the audio are about 0.5 seconds out of sync...

When this DVD was released I posted to a Clapton newsgroup to find out if they had fixed the problem. Apparently not, but I need to get more info...

I *believe* that Led Zeppelin's performance was left of the Supershow DVD, but it can now be found on the Zeppelin "DVD" released a few months ago. Perhaps the band owned the rights to their performance...

I'm waiting to see Supershow go down in price before I will pick it up...