Yes Mudguard,it appears that site isn't accessible today. The Mudcat evidently isn't the only site with these problemes. It's "The UCLA Language Material Project", which has some very handy stuff on it.

As for Urdu and Hindi, I'm going by what I've been told and have read. Here is a site which goes into the similarities and differences:

"At the level of the colloquial language that is spoken spontaneously or is heard in Bollywood movies, Hindi and Urdu are virtually the identical language. Thus,

gãv meñ voh lajavab hai.
[There is no one like him in the village.]

They are, however, written in two different scripts, Urdu in the Perso-Arabic script and Hindi in the Devanagari script of Sanskrit..."