As I was comparing Kindle DX and Kindle 2 I’ve noticed that some of the keyboard shortcuts that originally worked in K2 now don’t. Pressing Alt-6 used to type question mark, Alt-7 – comma, etc. Now these don’t seem to work in my Kindle 2. It looks like this functionality got disabled with one of the software updates: 2.0.1, 2.0.2 or 2.0.3.
Can you please check your Kindle 2 and verify if this works or not and post your Kindle software version. You can see this version in the bottom portion of the settings screen.