use psn patch to spoof your cid even if its original cid, this will fix it.. and because u have to use psnpatch everytime b4 sign in theres no inconveniece.. so u have to goto multiman/filemanager/hdd0/game/BLJSxxxx/USRDIR/default.cfg
copy default.cfg to pc and enter your cid in there.. then put back were u got it from after you save default.cfg ..
when u spoof ur cid on dex it will work.. other wise .. you need itamanager install it the run itamanager/press.start/networksettings/restore original cid.. bam