The Pink Panther/WMG

The 2006 reboot takes place in the same universe of that of the original films and the Clouseau played by Steve Martin is actually Jacques Gambrelli, Clouseau's son
And the Dreyfus played Kevin Kline is actually the original Dreyfus' (Herbert Lom) nephew, who coincidently is also called Charles.
 * When the movie was first announced in 2001, press releases did say that Steve Martin would be portraying an older version of Clouseau's son.

Clouseau never underwent Magic Plastic Surgery
Either Clouseau was kidnapped or killed and the people responsible for it hired Roger Moore to make the audience believe Clouseau changed his face.

Clouseau is God
Or at least God loves him that much, explaining why Clouseau survives the most deadly dangers in the world, everyday.

Dreyfus did not die at the end of Strikes Again
Several possibilities exist:
 * Clouseau traveled back in time to save Dreyfus.
 * Dreyfus did die and is replaced by a doppelganger.
 * Strikes Again is technically non-canon to the other films.
 * It was All Just a Dream from whoever's perspective it was.
 * Dreyfus re-materialized in his cell in the insane asylum from which he escaped.

The Ballon mansion was cursed, and the curse could only be broken when only one person remained.
For every time Clouseau came close to solving the mystery, another body was found. The explosion at the end ended the curse forever as Maria Gambrelli was all who survived.