Now that we are deep into the season and every team has played 30+ games, there isn't much impact at all when any single opponent wins or loses.
It's kind of like how a single hit affectes your batting average early in the season, but by late in the season when you've had lots of at-bats, then one hit doesn't bump your batting average very much.
Example...last night the team we beat in the BracketBuster, VCU, WON...and yet our RPI remains unchanged.
(it may have even dropped a bit as the NCAA site had us at RPI 44 on Monday morning)