I’ve seen something like this before. I’ve got 4 battery remotes, 3 Sony and 1 Technics and all four have them have simultaneously stopped working. I use them to control a DVD player, a TV, a stereo receiver and a CD player. All devices are in the same vicinity. What gives?
My best guess is one of the remotes has a key stuck down, and the signal it’s emitting is jamming all the others. Pull the bateries from all of them, and put them back one remote at a time, and see if you can narrow it down. Also look at them and see if you can see a stuck key. If not, it might be dirt or moisture under the keymat making a contact.
Along the same lines, make sure you have EVERY remote. TiVo is particularly sensitve to this issue, and one common culprit when troubleshooting a TiVo (I know you not talking about a TiVo specifially, but it’s just where I picked this trick up) is to check under couch cushions/in magazine racks. When remotes fall into cracks like that, it tends to hold a button down, but still leaving the front of the remote sticking out enough to make IR contact with the equipment. One person on the TiVo board actually found the remote by using an IR camera (cheap on ebay) to find the remote.
Or just cover the front of the remote with your hand, one at a time.
Well, sure, if you want to do it the easy way… 
Things started working after about 10 minutes. I don’t know what caused the problem. Maybe a neighbor’s remote? It could have been a stuck button - that’s probably the most plausable explanation.
Might it be an IR source other than the remote controls, such as the IR port on a laptop or PDA, or even a toy of some kind.
Ordinary CMOS webcams are quite sensitive in the infra red - if you have one and the problem recurs, use the camera to look around the room - IR sources will show as a bright white light.
it is likely that there is/was a bright light on that essentially “blinded” the sensor. Sunlight in particular can do this but so can any bright light really.
Some people have trouble with flourescent light fixtures or compact flourescent bulbs in the vicinity of IR remote-controlled equipment - they can flicker in the same frequency range IR remotes use. If you’ve got lamps like these in the room, try operating the remotes with the lamps on, and again with the lamps off.
I was going to start with the basics, such as, “Have you paid your utility bill?” 
CCDs are sensitive to the infrared. To the best of my knowledge, a CMOS will not pick up the wavelength a remote control uses.
They sure will. Better than a CCD in many cases.
You’re right about the CCDs (I just tested it with my Sony), but CMOS cameras certainly do pick up IR (I have tested this in the past with a TV remote and my Quickpix PenCam and with a cheap Logitech webcam - both of which were CMOS-based) - I’ve just tested it again with the only CMOS device I have - an IntelPlay QX3 microscope - and it does indeed pick up the IR from TV remotes as a bright white light.