The document autorecovery code always attempts to open files in their original format, despite the fact that autorecovered files are always in ODF. This results in autorecovery failing and deleting the backup files. This is fixed upstream in 3.4.2 - it would be nice to have it fixed in F15. Patch is at http://cgit.freedesktop.org/libreoffice/libs-core/commit/?id=6c397dfce4f7afddb55329b738388ab4eb16b7f8
fair enough, backported, will be in >= 3.3.3.1-7 if(when) we push another update for f15
this got pushed in a F-15 update