R help - Feb 2013 - Scraping data from website---Error in htmlParse: error in creating parser

I'm trying to scrape football projections from accuscore.com for the
different positions (right now the projections are set to zeros, but that
will change).  I can get the QB projections, but I can't get the
projections for any of the other positions (e.g., RB).   How can I get the
RB projections?

I'm not sure what the actual website for the RB and other projections is.
 When I go to the main website for the football projections (
http://accuscore.com/fantasy-sports/nfl-fantasy-sports/), it displays the
QB projections.  When I click on another position (e.g., RB) it displays a
new URL (
http://accuscore.com/fantasy-sports/nfl-fantasy-sports/Rest-of-Season-RB).
 When I enter this new URL into the readHTMLTable function, I receive the
following error:

Error in htmlParse("
http://accuscore.com/fantasy-sports/nfl-fantasy-sports/Rest-of-Season-RB/")
:
  error in creating parser for
http://accuscore.com/fantasy-sports/nfl-fantasy-sports/Rest-of-Season-RB/

What's going on?  Might this have something to do with Javascript?  How can
I scrape the RB projections (
http://accuscore.com/fantasy-sports/nfl-fantasy-sports/Rest-of-Season-RB)?

Thanks in advance!

library("XML")

#this works fine (QB projections)
qb <-
readHTMLTable("http://accuscore.com/fantasy-sports/nfl-fantasy-sports/",
header=1)$fantasy_table

#this produces an error (RB projections)
rb <- readHTMLTable("
http://accuscore.com/fantasy-sports/nfl-fantasy-sports/Rest-of-Season-RB",
header=1)$fantasy_table

	[[alternative HTML version deleted]]