I swear to God the Eclipse developers are deliberately sabotaging Subclipse to get people to switch to Subversive. It works, too. After twenty-four hours of trying to get a working Eclipse 3.5.1 + Subclipse + EPIC installation on my laptop, I’ve finally given up.
I suspect this also has something to do with Mylyn, but I can’t prove it.
Chrononaut 
Post your problems to users@subclipse.tigris.org. It ought to be possible to get you working.