WotLK Item is missing

[Rafaearth]

Just had the weirdest bug.

Bought a searing dagger on AH, equipped it and sold my old sword.

Got a bag from Gbank, it wasn't working so I logged out and logged back.

Bag working, dagger gone and sword back.

Went to the vendor to see if I had in fact sold my dagger and... Nothing.

How to proceed?

[OhieMitzen]

Check that you haven't just simple misplaced the dagger by going to bank and opening your bank tab, then open your character pane and mouseover your weapon, press and hold ALT, see if the dagger appears on small list that appears. If not, nothing can be done, you'll just have to take the loss and continue playing.