BTW I was reading this :
http://www.dragondoor.com/articler/mode3/69/
Grease the Groove for Strength: A Strength Training and Powerlifting article from Dragon Door Publications
and it made me sort of rethink my philosophy on how to work Rippetoe. You're doing a 3x5 three times a week. I realize now it's important to NOT go to failure. You're just trying to do pretty hard work, maybe around 80% of 1RM, so that you can do your sets clean, strain those muscles, but not go to failure. Not only will failure make it impossible to do good sets in the next workout, it might actually be counter productive to building strength.