I've had this discussion before and I thought what you thought. However I was proved wrong, without checking I think it was Widnes but not sure.

Cas and London were definitely in Super League at the time. For Widnes I think it was their first season in SL but hadn't played a league game yet.
It is still too long ago though.

Widnes had just got promoted, Cas were in Super League at the time and although I can't recall the London game it's only since 2014 London havent been in SL. Have we played them in the cup since then?

Incorrect on all three i'm afraid. We beat Widnes in 2002, Cas in 2003 and London in 2004, all were superleague teams at the time. Not too much to write home about since though, even the run to the semi's in '08 was on the back of playing all lower league opposition.

Correct.