I think that this is distinct from a supernova, actually. From the Supernova article:
"Type Ia: They don't have Helium, and present a line belonging to Silicon. They are generally though to be caused by the explosion of a white dwarf, at or close to the Chandrasekhar limit.
One possibility is that the white dwarf was orbiting a moderately massive star. The dwarf pulls matter from its companion to the point that it reaches the Chandrasekhar limit. The dwarf collapses into a neutron star or black hole, and the collapse causes the remaining carbon and oxygen atoms in it to fuse."
Both involve white dwarfs, but there is a very large difference between the sort of explosion a stellar mass collapsing into a neutron star or black hole would produce and the sort of explosion the mere fusion of a few teratons of hydrogen would produce. Hence the super in supernova.
Don't have time to dig up an actual reference right at this very moment, though.
I'd trust you. :) The thing is, though, the page is not just talking about a nova, but a final explosion which rips the white dwarf apart. As far as I know, this should happen basically when the novating star reaches the Chandrasekhar limit, and so would be identical to a type Ia supernova. Except, thinking about it, for that bit about silicon - a naked core should easily be able to destroy itself with a helium or carbon flash. Hmm. I guess I'll change it back, and leave this as a note that further research is needed.
The distinction is an important one. A nova can occur over and over, as the orbiting white dwarf sucks material from its companion star and ignites it, boom!. A Ia supernova sucks matter from its companion, yes, but the key is that it sucks so much that it goes over the Chandrasekhar limit and BOOM! It's far more energetic, and the majority of the energy comes from a different source (the body of the white dwarf).
If you want a simple rule of thumb, a nova can (and often does) occur multiple times, while a Type Ia supernova -- well, to quote Daffy Duck, "You only get to see this trick once". -- Paul Drye