I am not sure where this information comes from, but I have never heard of that indcident. When he took the throne, he did invite all the royal administrators that were left over from the previous administration and kill them at a banquet to vanquish his enimies within the government.
Also, the name he was tagged with was Dracool, not exactly Draula, as we say it now.
I'm with you,
I know about him killing the 'nobles' or administrators after a feast, but I've never heard this story before.
Vlad and the whole 'Dracula' legend is one on my favorite bits of history.