The mastertapes of Episodes 468 and 469 were stolen, and therefore couldn't be shown. They will be shown at a later date when they have been refilmed.
News article from Digital Spy on the thefts: (10/11/2006)
Two mastertapes for television programme The Bill have been stolen from ITV, along with two editing machines worth £10,000.
The ironic burglary took place at the TV station's studio in Merton, South West London.
The thief was reportedly wearing a high visibility jacket and followed a real worker into the editing room, before taking the machines and being driven off in a van parked outside the studio.
ITV bosses were apparently fuming when they heard the news. An insider told The Sun: "It's not just the expense, it's the disruption to filming. It's embarrassing as we're supposed to have a good handle on how thieves operate."
The police confirmed that no arrests have been made as yet.