4.1.5 on Drupal 6, deleting contribution page deletes WAY too many contributions

[flug]

Recently I upgraded from CiviCRM 3.3 to 4.1.5 on Drupal 6.

Later, I deleted some contribution pages.   These were pages that only had a few test contributions and had never been used 'live' or had many (or in most cases, ANY) actual/live contributions made with them.

When contribution pages are deleted, the associated contributions (and other related items like addresses and activities) are all deleted.  That's fine.

However in this case, many-many-many more contributions (and addresses/activities) were deleted than should have been.

In fact, pretty much all the contributions in the DB were deleted.  About 15 were left out of about 850 that were there originally.  I would have expected maybe 50 contributions (mostly test contributions) related to the contribution pages I deleted to be removed, but no more than that.

Even contributions received through events were deleted entirely (these don't have a contribution page listed in the database--that field is 'null').

Any ideas what could be the cause of this?  Is it a bug or just some normal behavior that I was not expecting?

My pro-tip for the day is: always make a full DB backup before deleting any contribution pages.  (Maybe it would be wise to add this advice to the warning message before contribution pages are deleted.)  Luckily I had an automatic DB backup created pretty much just before I deleted these contribution pages.  Without that, the problem would have been pretty serious rather than just time consuming to fix.