There is a lot of equipment the remotes will not work with. I have a sony cd recorder and a high end HK receiver which none of Dishes remotes work correctly with. The remote will control the volume on my HK but its reversed. The volume up is on the left and volume down is on the right. +- It's so aggravating it is useless. For your sake I hope you have better luck than I do.
They don't work too well. I have a samsung plasma and I can turn it off and access the menu but I can't go down through the menu or change settings, I can turn it off. Damn friend lost my remote for my tv so my only way without getting off my ass unfortunately.
A real learning remote would have a button to put it into learning mode. you would then face the remotes at each other and press a key on the learner and then press the corresponding key on the teacher which would then transmit the signal to the learner.
As far as not supporting a plasma, why not? They are just TVs.
It is unfortunate that there are no industry standards for remotes. Say, each mfgr would be assigned one or more numbers. All their codes would be required to be consistent (e.g. all TVs would use the same signal to increase the volume). New features would add signals so remotes would be backward compatable. This would mean old remotes would work fine on a new TV at least for the buttons on the remote. And new remotes would work with old TVs.
The remotes would send out a mfgr number at the beginning of each transmission which would correspond to the setting on the device so a channel up from a remote would have a different beginning number for each device (VCR vs TV). Remotes could be "programmed" for the device (like the Dish remotes for UHF) and the devices could have the numbers set so that if you had 2 Sanyo TVs side by side, you could set separate numbers on TVs and remotes.
Then you could buy a Philips DVD recorder and a Apex TV and set the recorder's remote to control the TV.