http://smart-home-blog.com/archives/656
From the smart-home-blog, an excellent site with some very neat Pluto development/useful feature explanation. I believe this is applicable to LinuxMCE, but I haven't tried it yet.
MythWeb is installed by default with LMCE. I use it all the time. I actually prefer it for scheduling recordings over using the MythFrontend.
What URL are you following that allows MythWeb to be accessed. I have reinstalled from scratch and checked this again.