I've been having this issue where my S3 runs into a symlink failure/Status 7 error whenever I try to flash a Jelly Bean rom, ie. CM10/PA/Jellybro. This occurred despite me having the latest 220.127.116.11. CWM, wiped and reformatted EVERYTHING, etc. I posted a sample of where the recovery error log shows the flashing processes failing here:
Lots of XDA member offered advice with no avail. I remember one member mentioned something about partition tables, so I dug a little deeper. I noticed that the error log also contained error messages about missing directories and my sd-ext not mounting, which is strange since I can access my external sdcard under /mnt/extsdcard directory, and the two directory names aren't matching. So I downloaded an partition table app and saw the following:
Basically, it looks like my partition tables are somehow corrupted and my sdcard and external SD is being mounted for use, but somehow...incorrectly. I'm thinking this is the likely culprit.