I don't have this issue when turning pages only when playing with the menu sometimes like to change fonts or to bookmark. It's almost always happens when using the bookmark options. I now wait for the light to go out each time before hitting the next key. This seems to solve the issue for me.
I'm using December firmware with a Sandisk 8gb SDHC card. I'm still on my first charge from March 5th. Battery is still at two bars.

I only use MOBI/PRC files so can't comment on page turning for other formats but no missing key presses while reading them only when playing with menu options it sometimes happens but letting the light go out then pressing the next key works just fine fixing that issue for me.