Updated estimation of S2S min

eBay published its quarterly results. I therefore updated my personal tables to prepare some posts later on.

However, I noticed something weird in the Skype to Skype minutes …

The data in the red ellipse comes from the presentation of Quarter 3 2007 results.

The data below the red ellipse, comes from the current presentation published yesterday.
I looked several times to both tables, and they have the same legend. However eBay upgraded the number of minutes served by a very significant amount, quarter 3 2007 raising from 6.1 to 9.8 billion minutes served, this is a correction of the original data of more than 50%.

• Did they make a mistake and did they correct it?
• Did they improve their measuring algorithm, and did they do a backward calculation?
• Or did i miss something?

[edited:] I missed something, the slide says "Skype-to-Skype minutes are estimated; prior period amounts are updated to conform to current estimation methodology."