Hey Arnold!

[infecti0n]

I seem to remember there being an episode of Hey Arnold that was in 3D. I think Helga bought a love potion or something like that to make Arnold fall in love with her. Does anyone know the name of this episode or was it some sort of movie?
It's been driving me nuts for a while. I tried to google it but nothing came up and I don't want to spend forever on IMDB trying to figure it out.

Thanks :)

FOUND!
Helga's Love potion (her dream sequence)