I feel your pain OP!
Having had a few nasty incidents of losing data due to computer crashes (if it crashes while Opera is open all sorts of data files can be corrupted, bookmarks, history, wand data etc.) I now back up my whole system to an external drive every week, something I would recommend everyone to do.
I'm also in the habit of regularly saving backup copies of files like wand.dat as wand.dat.backup in the same folder.
These won't get trashed if there's a crash, and are easy to restore just by renaming them.
That's no help now of course, but I would recommend getting hold of a free undelete program (I use Undelete Plus, but there are others) which will scan your hard drive and show you any recoverable files.
You may be lucky and find a copy of bookmarks.adr which hasn't been overwritten yet and may be recoverable.
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