Hi,

Some of the cards are showing up as illegal in Standard, altough they are legal:
Boneyard Wurm
Brain Weevil
Dissipate
Ravenous Rats

Those are just the ones I've found in my inventory. I assume this is due to Dual Decks Izzet vs Golgari being the latest edition.

That was exactly right, we've imported the Duel Deck wrong.

Legality information has been fixed for these cards now.