Backstab: what can thieves back stab with? Bows?
I tried Tansheron's Bow but it didn't work!
I hid in shadows went behind this Ogre:

Weisi Attacks Ogre
Weisi Leaves Shadows
Weisi does 3 damages to Ogre
Ogre attacks Weisi
Imoen: Cone of Cold Ogre
Ogre very quick Dry Freeze Death

Thieves can backstab with any MELEE weapon that a true class thief is allowed to use; in other words longswords, shortswords, katanas, scimitars, ninja-tos, wazikashis, clubs, staves, and daggers (I hope I've included everything here). Note that there are a few magic staves, for example the Staff of the Magi, that are not usable by thieves, so a multi- or dual classed wizard/thief using one couldn't do a backstab.

THANKS...so no bows?
Err I'll stick to the equalizer than...such a rubbish sword but all the goodies are used!