Alpha 1 installed and ran, but there was another problem wihch I now can't remember. I went back to 12.10 until audio failed, then 12.04 until audio failed there too. All the subsequent versions from albha 2, alll the betas, and the stable release 4/25 have been normal up to the foint of the desktop screen. There ir seems to go out of sync: I get a repeating pattern, which is wider than the screen so that it wraps and creates a diagonal pattern of repeated segments. When I go back to 12.xx, they are normal except for the audio problem. Occasionally I can get past the problem initially, buh the change to an app screen throws it off again. Ideas?

I think you really need to provide more info here.
It seems unlikely that a first alpha would be work ok, but the final release would be not. Clearly something else must be wrong.
How exactly did the audio fail?
What sound card do you have? Have you checked if proper drivers are running? Have you ran alsamixer?
If your audio was fine the whole time you used 12.04, and then 12.10, and then you reinstalled both of those versions, and now the audio does not work, I think you should first rule out a hardware problem.
Does the audio work reliably when running live CDs?
Here you should at least tell us what graphics card you are using, and if you have installed proprietary drivers or you are using the open source drivers (ATI? Nvidia?).
Have you checked the Xorg.0.log for errors (EE)?
Does the video also work reliably from a live CD??

I do not claim to have the answers here. I am just trying to help with the questions.
Hopefully we can figure this out.