so i upgraded a blog from 2.6 to 3.1 and the entries were not automatically assigned basenames in the mt_entry table
then i changed the archiving style to textual, and all the archives were given page titles of dirify($entry->title).
but then for new entries or entries that are edited (and saved) post-upgrade, the entry_basename field gets populated, and then you have dirify() but truncated at 15 letters (whos idea was that truncation??!?!?).
this is just wierd behavior. i think the truncation should be an option that can be set to some # of characters (not HARD-CODED to 15) or to no limit at all.