Owners of Blu-ray DVD players may find themselves frozen out of future developments in the technology because their machines are not upgradeable.
The Blu-ray camp has recently rolled out new features for players, which include picture in picture options.
But the majority of Blu-ray players sold to date do not have the necessary hardware to offer the features.
Some discs already come with a note telling users that they may need to upgrade software in their machine.
In some discs, the note reads: "To ensure the best possible viewing experience, your Blu-ray disc player may need a firmware or software update."
But these updates relate to improvements in playback and do not offer a pathway to the new features.
The issue has arisen as Blu-ray attempts to offer new features to compete with rival standard HD-DVD.
When the first Blu-ray machines were launched the hardware requirements for manufacturers did not include provision for planned developments.
The guys that bought the first Blu-ray players are the guys who bought the first laser discs. They know the risks.
Alastair Upham, DVD Review
Instead Blu-ray players were divided into so-called "profiles", with all machines released before November 2007 designated as profile 1.0.
Machines released onto the market since November are called profile 1.1, but none of the standalone Blu-ray players can be upgraded to accommodate this profile.
Films will still play on the machines, but access to extra features is limited.
Later this year the Blu-ray camp will offer profile 2.0, called BD Live, which will allow the players which support the feature to connect to the internet to download related content, such as ringtones, trailers and photos.
But because internet functionality is not a mandatory requirement in current players, none on the market today will be able to access the feature.
The only Blu-ray player which can upgraded to use all the features is Sony's PlayStation 3, because it comes with the right hardware built-in and online access.
