Note that having a certain Characteristic does not necessarily imply that the highest possible value for an IV is present. A Pokémon with an "Alert to sounds" Characteristic could have a 6 in Speed (and thus very low IVs across all of its stats since none could be higher than 6) instead of a 31 in Speed.
Mistranslations
In Generations IV and V, two of the Characteristics were not properly translated from the Japanese releases. The HP Characteristics corresponding to IVs of 1 and 2 were accidentally replaced by the Characteristics corresponding to IVs of 2 and 3, respectively. So, rather than the HP Characteristics being ordered "Takes plenty of siestas", "Nods off a lot" (i.e., "Often dozes off"), and "Scatters things often" as they should have been, they were ordered "Often dozes off", "Often scatters things", "Scatters things often" (note that the last two are different, but only trivially).