[spoiler]
Generation I to III
Thunder Wave paralyzes the target. Thunder Wave can't affect a target that already has a major status ailment, and will not work against Ground types.
From Stadium onwards, Thunder Wave can't affect a target that has a substitute.
Thunder Wave is unaffected by Volt Absorb.
Generation IV
Thunder Wave now can't affect Pokémon with Volt Absorb or Motor Drive.
Generation V
In addition to the same effects as before, Thunder Wave now cannot affect a target withLightningrod.
[/spoiler]
If it's really affecting them, i think it should be changed.