Found this on GEOS
The word around the campfire is that due to increasingly good sales on the Futurama DVD sets and Video Game, Fox may be firing up the grill on another season of Matt Groening’s show.
The series, which was on air for four seasons, never reached the heights of popularity achieved by The Simpsons, but was applauded by critics & fans everywhere. At the time the show was "pulled indefinitely", the rumour was that at least another season of the show was in the early to 50% complete stage of production, and may be "revisited further down the road".
Well, according to a couple of sources, they may just have gotten a little further down the road, so hopefully for fans of the show, there will be more Fry, Bender, Leela and Dr. Zoidberg on the way this time next year!
This is from September 2004 (a month after the US release of the 4th season DVDs), so if anything like that happens, its logical it would happen after high 4th season DVD sales - so the time seems valid.
The source is a weird site called "Movie hole"
which doesn't exactly look like a reliable source.
I couldn't find this post anywhere (its pretty hard to search for such a thing on this forum, since "Futurama references threads" are really common) - hope this wasn't posted before.
Anyway, up to you to prove it as false.