I don't really think that it's fair to blame Amazon for problems you have running their app on older hardware with a gray market ROM image.
It's hard enough to run tests on the legitimate Android configurations active on the market. Trying to account for homebrew setups like Cyanogen would be a recipe for lots of pain and effort with very little payoff.
How is Cyanogen any different from any other Android 2.1 image?
I have the same issue - apparently this is a bug in Cyanogen mod (or at least they have a fix for it) - http://code.google.com/p/cyanogenmod/issues/detail?id=1663#c...
Who knew that rendering a subset of HTML could be so difficult...