use rebug and toggle fake save data owner on.
or you can try copping the save files via multiman except the param.sfo over your save and overwrite it.
your saves are under dev_hdd0/home/0000000X/savedata/...........
where 0000000X Represents your UserID, Just count down from the 1st user to your profile, for example User 1 is 00000001.