Memberships in lists vs reports

Hi all,

I'm looking for some guidance as to whether the following is a) user error because I'm so new with lists in V 11, b) some kind of migration issue, and/or c) an actual bug.

I'm pulling a list of members with an expy date between 2/18/12 and 2/20/12 for testing purposes. 

A) Pulled the list using "Membership Current Expy Date" between 2/18 - 2/20/12 with "Search household" checked and "leave individual constituents as selected."  This yielded 1333 accounts - WAY too many.  Clearly it pulled all the households as well as ALL their affiliated individuals.  OK...

B) Repulled the same list but checked the "Replace individual constituents with their primary household" box.  Got a much more reasonable 467 constituents.

C) Ran two separate reports, both "Membership expiration report" and "Membership Details" report, for the same expy range - both of them gave 483 constituents.

SO:

1) Can anyone help me understand why A included the affiliated people, even though the contributions and memberships live on the household record?

2) Why are the reports coming up with more constituents than my list?  A merge/purge shows that all but one of the people excluded from the list but included on the reports have a pending membership; why isn't the list picking those up, even though the current record is in fact the Active one, not the pending one?

Thoughts?

Thanks, everyone!

Beth