Oh. . l agree. That's why I only suggested using it as a second flash i.e. not on the camera, but only if you need to keep it for a canon system. Otherwise I would sell it.I was always kinda ticked off that Canon never included an Automatic (thyristor) mode on most of its E-TTL flashes. Then suddenly the 580EXII came with it and it was severely crippled (and prone to incorrect exposure). Even on the 1DmkIII it was kind-of a useless feature.
Forget about the fact that it's pin-similar on the hotshoe. It will not operate properly on the Oly. Even using it in Manual mode, there's a slight chance that it'll confuse the Oly electronics because of the constant digital "banter" Canon flashes have with canon bodies when attached to the camera and those data pins don't carry the same signals..