a.b.boneless had a 4+ GB storage*.db3 file. Hadn't been updated since 2011-Aug. I set my display age to 30 (I know), and then requested a 'Post Storage' -> 'purge to display Age'. It ran for 5-10 minutes. Afterwards I saw there was no change in space usage. I then requested a compaction. This ran for a few seconds and still no change in size.
I set DisplayAge = 2 and went through everything again. No change in folder size - still using 4+ GB. Finally I deleted all records, with a compaction, and folder shrunk to 27 MB.
I started a compaction and it claimed it recovered 160000 TB. I restarted Newsbin and compacted again. It says 0MB reclaimed. Still 27MB used.
Unexpected by me.