[modeless]

How can that be if the standard was ratified in 2003?

[wmf]

Perhaps some of the patents cover optimizations that don't affect the bitstream format. Or maybe they're just bogus patents.

[jws]

Some of the patents may have been applied for, but not granted until after ratification.

[modeless]

For patents filed after 1995 the patent term is based on the filing date of the application, not the date the patent is granted.