The RPI and SOS may be significantly skewed early in the season because there are so few games to base them on. The RPI is primarily a measurement of strength of schedule, and how the team did against that schedule. Each season stands on its own. There are no preseason expectations - everyone starts at zero. Consequently, the numbers could be really skewed early in the season because teams have played so few games.
For example, a team can be 2-0, but its opponents haven't played anyone else yet, so its strength of schedule is 0. That's 75% of the formula, so the team won't be rated very highly. After game #7, enough games have been played to start to give a realistic view of RPI and SOS.