I'm not sure where you get this. All I see is that it's a "Survey of 928 Adults Who Regularly Attend Church." Perhaps you have a subscription for the cross tabs?
But where's the agenda ? I don't see it in the poll itself. All I see is a DIFFERENCE in emphasis.
A difference if emphasis is a bias. That's how you bias a poll, by the questions you ask. Here's a link to the questions:
http://www.rasmussenreports.com/public_content/lifestyle/general_lifestyle/general_lifestyle_toplines/toplines_churchgoers_december_16_2008
"pray to confess sins" ? WTH is that? I could attribute it to ignorance, but almost all the questions aren't relevant Catholic's practice of their faith.
Perhaps it is the title that's misleading: If it were "Catholics Don't Do Sola Scriptura, OSAS or Easy Believerism" it would be more accurate. :)
S&F, the poll is a blatant Protestant poll. They should have left the comparison part out of it.