I can't find anything on the www, perhaps someone here might know the answers.
1] Shutter button not working... Shooting in controlled environment, no grip attached, off-shoe flash cord attached, lens used Sigma 18-125. Problem: "all the lights are on, but no-one home". The shutter button doesn't do anything. A quick removal/insert of the battery gives an instant remedy. No error message(s). Tried 4 different cards. Not tried with another lens yet. Anyone experience this?
2] Tethered shooting... Software works fine, but I can't seem to get an external flash fired when shooting tethered. What am I missing?
my 20D used to get finiky when the battery got below half, even though the battery meter shows full or 1/4, the 20D wants more juice
also, at one point, my shutter button went out, at first reboots helped, but only for a few shots, then eventually, it quit working entirely, so off to Canon for repair ... that was back in '06 ... worked fine until this fall, now it isn't working again & I suspect the shutter finally went out
luckily I have 4 other bodies, so I'm not in a hurry to repair the 20D, may just buy a 7D instead and keep the 20D as a paper weight
I can't help with no. 2. No. 1 has happened to me also. I think it is the seating of the battery. I may not have had it in all the way or not a good connection. Taking the battery and reseating has always fixed it for me. I've got to where I put the battery in and give it an extra push. I haven't had anymore problems.
A lot people have problems with the shutter release button failing on the 20D. It may be that. I know my 20D is having issues where sometimes when I half press to focus and then press fully to take the shot, it refocuses. It is not constant and happens every now and then. It's an issue with the contacts in the button switch. You can try taking apart your 20D and cleaning the switch as shown in this video if you're brave enough:
Marcel, what os are u using? I've been wanting to shoot tethered with my 20d and Vista 64-bit and everyone in the forums have told me that that cannot be done...
and keep the 20D as a paper weight