Getting new cards
In Match Duels or Single Duels, if the card that was won is not a new card(s) (i.e. says "NEW!" across it as you acquire it), click just below the card (middle card for match duels). You will be given the option of getting another card.
Wrong card behavior
While the Trap Card "Magic Thorn" is active on the field, when your opponent discards any number of cards from the deck (for example, Needle Worm, Gravekeeper's Servant) it does not count as damage to Life Points, and the card just says discard. The card was supposed to activate even if your opponent discards from its deck.
Faster duels...