i have the very same issue, i am following the official guide from vitahax guide..
installed adrenaline vpk, then opened it to have it download the pbp, then went to vitashell and moved the 661 pbp from the ux0:adrenaline into > ux0:app/pspemucfw (there was already a 661 pbp present there) i simply replaced it there.
then i deleted the adrenaline folder from the root of ux0
then i am supposed to open the adrenaline application again, and when i open i get kicked back to the live area :l
edit: a reboot fixes the issue (needs to be launched twice, use the guide to fix that) happy gaming.