Not quite Z related, but interesting in this context. I just bought a Canon A710IS, which has been sold for less than 6 months.
Seems that tho' the camera is SDHC compatible, it doesn't work with old standard 4GB SD cards. It gives every appearance of doing so, but doesn't actually write anything to the card!
I upgraded from an "ancient" (6 years old) Olympus C-3040Z (which took 128MB smartmedia cards, nice photos, slow to work) to the Canon A710IS (bargain off ebay!).
The Canon comes with a 16MB card, pointless since at highest quality image files are 3MB each! So, I slotted in my non-HC 4GB SD card, and took a few pictures to test it (didn't even bother to unwrap the 16MB card, seemed a bit pointless!).
Pictures looked great on camera, plugged camera into Linux PC to transfer pix, no pictures! Hmm. Took more pix, put memory card into PC's usb card reader, no pictures. Put test files onto card on PC, plugged into camera, turned on, took pix, back into PC.... etc... repartitioned card into a 1.9GB fat32 partition, still no pix stored. Very odd. Worried that camera was broken, plugged in my Lexar 1Gb card (previously in use in Z, now in my Palm T3), and it worked fine!
So, moral of the story, even Canon can't get compatibility 100%