The above video goes away if you are a member and logged in, so log in now!
i wonder if that is a well-known thing, but irshell can be started from xmb with one of the two loaders - one for 1.5 kernel and one for newer ones.
if you start irshell from xmb with 1.5 launcher and you want to install the pspbtcnf.irx patch, if will fail with some error code. i thought there was something wrong. apparently i had to relaunch it with the other launcher, and everything started working ok.