Decided to start a new topic for my new problem. Forum member usayit did try to warn me about this but I'm still unsure if this is a problem with the flash or my camera. The other topic can be found here . . . http://www.thephotoforum.com/forum/viewtopic.php?p=101663#101663 Here is what I have now . . . Canon 10D DSLR body Quantaray PZ-1 DSZ TTL Flash Quantaray QTB 7500-A TTL Flash My problem/question is why will the cheaper QTB 7500-A TTL Flash fire on the 10D but the more advanced PZ-1 will not? Everything will work just fine except the distance scale and it will not fire in any mode at all. It was my understanding that this flash would still work in TTL mode or at the very least in manual mode. Is there a problem with my camera or am I stuck with an E-TTL only flash such as the Canon 550EX? The PZ-1 does however perform flawlessly on my Canon Rebel 2000 film SLR body.