I went thru this before, and searched for the answer, but can't seem to find it.
I remember as soon as I got to the log on point using a command and unloading laptop mode and some other things to free up memory so I could get LXDE to start/install.
What's happening is I start LXDE from the livecd and in like 5 hours or so I seen a desktop once. Usually it hangs at the wallpaper.
Yep, checked md5sum, it's correct.
burnt two copies of LXDE one at 8x where I know it will work and another at 1x.