Migration to BusinessObjects Enterprise XI 3.0 - part 5?

The question mark in the heading above states that I am not completely sure at this time that the issue described below is due to the migration phase.

We have noticed a strange behaviour in one of our Universes in the BOE XI 3.0 environment. The Universe has been migrated from BOE XI R2. The Universe has a last modified date that is newer than the date in BOE XI R2 environment. Ok, that is not very strange. The strange thing is that the revision number is identical! And we know for sure that the Universe has been changed. One inner join (BOE XI R2) has suddenly become an outer join (BOE XI 3.0). One more observation is that the last modified by user also has changed. As no one (as far as we know) has changed the Universe these questions arises:

• Why has the join changed if no one has altered the Universe?
• If no one has changed the Universe and the join has been altered due to an migration bug, why has the date and user changed?
• If someone has changed the Universe, why is the revision number identical between the systems?

The new date in the Universe is not the migration date.

Strange stuff is an understatement. Do anyone have an reasonable explanation for this?