I have a friend looking at an early 06 built 997S. It was first sold at the end of 05 and I haven't been able to find a clear answer as to when porsche figured out and addressed the problem.

 

According to Excellence Magazine (April 2010) the new single row IMS started with engine # 661 14165. Note that's the engine # & not the VIN #.

 

Need to check the engine serial number on the bottom passenger side of the engine. If it starts with M96 you have old bearing. If it says M97 you have larger new bearing.

To clarify, it's a bearing and not the seal that is larger. The older style can be upgraded to a larger bearing (3rd party, not Porsche) for about $2,000.