Fixing the Membership Details report in 4.4.3

[David Hepper]

CiviCRM 4.4.3:
When running the standard Membership Details report we find that the Preview shows 841 records, including those with expired memberships and deleted contacts but when Printed or Exported there are far fewer - 411 - since mostly only current memberships (with a few expired) are included. This problem appears to be fixed on the 4.5 Demo site, where all records are exported, but I'm not sure. The following may be significant:
At the top of the Preview:  "Contribution Status Is one of Completed"
At the top of the Export:   "Contribution Status Is Completed"

Even stranger, after navigating around the Preview it suddenly changed to show only 411 records - the same ones as in the export! But I'm having trouble reproducing this. At the moment it resolutely shows 841. I did not change any of the Report Criteria.

(re-edited to add extra info at 14:03 GMT)