Hi there guys, long time reader, first time poster:
I suffer from this issue on my Mygica ATV1200 with my logitech bluetooth keyboard.
I made a temporary workaround based on a user called Awol which I found on the xbmcandroid forums.
The bad:
It doesn't really fix any of the "broken" keypresses.
The good:
It allows you to map the functions of the "backspace" and the "escape" keys to different ones.
The fix:
To change keys one has to replace or edit the keymap.xml file located in <insert location of SD card>/Android/data/org.xbmc.xbmc/files/userdata/keymaps/
My keymap.xml file contains the following added hotkeys.
h (for home) = escape
f (for favorites) = favorites
\ (aka backslash) = backspace
If you want to, you can change the buttons in this xml files, it's not exactly rocket surgery. Just remember that thing listed under "global" work from all locations within XBMC and things listed under FullscreenVideo only work from the "Now Playing screen"
The keymap.xml can be found here:
http://www.knuffelbaar.nl/xbmc/keymap.xml
I hope this helps you guys out for now until the issue gets fixed by the devs.