quick update, I'm looking at doing the key mapping via xmodmap instead of through LMCE. Hopefully I can get it to do what I want/need for controlling Myth. Maybe even for LMCE? If I get it going good enough to control UI2 (video playback is the biggie) I'll post up a quick HOWTO and possibly even try to figure out how to post on the wiki for those of us who would rather go with a dirt cheap remote that works instead of buying a UIRT+MS/FIIRE remote with all the bells and whistles.
Not sure if xmodmap is going to cut it for making it work in UI2 though, as far as I know there are no keyboard equivalents for direct media control and I'm not sure how to do it. The remote "does stuff" in xine but not in Xine_Player, at least not through LMCE.
edit: Is there anywhere that I can see what function is mapped to what key input? ie - what does the key "XF86Back" do in LMCE, if anything? How does the left arrow get mapped to "left" in LMCE? Or is all the mapping done outside of LMCE completely and it requires X to send it things like "live_tv" when the appropriate button is pressed?