I have an istD with 330FTZ, 400FTZ and 500FTZ flashes. The camera is in green mode and I take flash shots at ISO 200, 400 and 800 ASA all from a tripod, the same subject and the flashes in auto-TTL mode. The 200 ISO shots are all underexposed, 400 ISO is more or less correctly exposed and 800 ISO are all overexposed.
The IstD manual recommends 200-800 ASA for these flashes. The solution would be to allways use ISO 400 for flash which would be very strange. Jack
