ok, I read the whole thread as I was experiencing my own share-a-problems.. so, here's my own findings and experience on installing this pack; most than all a bunch of recommendations.. I was having the same trouble in running the brews specifically with the no load and poweroff issues.
Rec no. 1 .- if you have any saved games which occupy the 'slots' to be taken by the homebrew, delete them first instead of overwriting them.
Rec no. 2 .- if your problems go with running just one or a couple of the games if not all, don't unpack the whole bunch of saves at once.. you'll be better off copying them folder by folder..
Rec no. 3 .- the cheat device does not do shit to the new homebrew unless (and I'm just guessing here), a cheatdeviced game has just been loaded before.
Rec no 4 .- Downloading the pack again if you think the decompressing might have screwed the content DOES help.
I myself has having trouble to run all content at first (while I had been already able to play snakman and tetris on their independent release), then tried the first recommendation and it helped in getting two of the games to run.. then I tried downloading the pack again and trying both recommendations 1 and 2, while having the cheat device already on the memcard and even upgrading it in between tries =)
oh, and last recommendation on my behalf... don't rush it.. give your psp time to digest the info, to load the stuff (watch the blinking lights..) and then move on =)
happy 2.01+ homebrewing!
-ani-
oh, almost forgot:
Rec no. 5 .- To avoid autoloading of any of the homebrewed games:
First thing to do is identify on which slot is your actual gta save game (the one you're usually playing and making advance at) and relocate (or overwrite/re-save) it to slots 1 or 2 (note the save game numeration begins from zero, so this would actually be second and third place on the list).
When you have done this, do as it's been said earlier on the thread, when you're copyin the files onto the memcard, also remember to move your saved game 'slot' out to the computer, then back into the psp so the autoload recognizes it as the most recently created file and doesn't load the homebrew on startup or either make you HAVE to remember to get the memcard disconnected from the system AND have to load the intro scene over and over again..