A shortfall in global sales of DVD releases such as The Incredibles and Shrek 2 has sparked fears of a downturn in the DVD market.
The Incredibles was among the biggest box office hits of 2004
One million too many DVD copies of The Incredibles were shipped out by makers, while Shrek 2 producers DreamWorks overestimated sales by 10 million.
Some analysts said the figures marked a shift in the home entertainment market rather than a slump.
An initial sales burst then a rapid decline was expected to become a trend.
This pattern would reflect a box office trend, which sees movies perform very well in their initial weeks of release and then tail off rapidly.
Both Pixar and DreamWorks registered a fall in their share values after the sales announcements were made.
Nevertheless the global DVD market was still forecast to grow to $27bn (£15.3bn) in 2009 - up from $17bn (£9.63bn) in 2004, according to accountancy firm PriceWaterHouseCoopers.
Other analysts expressed concern that DVD retailers were replacing titles on their shelves more quickly that usual, in part due to the release of a number of television compilations.
Shrek 2 broke records for an animation film in the US
But Brian Lucas, a spokesman for US DVD retailer Best Buy, said there was "still lots of passion" for home cinema purchases.
"We don't have the sense of The Incredibles not doing well. Our general perception is one quarter of softening DVD sales doesn't make a trend," he added.
Despite the shortfall in DVD sales, Shrek 2 was the biggest grossing animated picture of all time.
DVD sales of The Incredibles have topped $450m (£255m) worldwide since its release last November.