Samsung Galaxy Tab 7

Help!! I rooted my samsung galaxy tab a few months ago and after the latest update(gingerbread) it says I am no longer rooted. I tried to reroot using kies but I keep getting permission denied. I tried removing the superuser app with a terminal emulator and the same thing occurs--permission denied. I tried to root using z4root and, you guessed it, permission denied. I found a custom rom to put honeycomb on my tab and wanted to give it a shot....but can't seem to get aorund this issue. I am sure I am not the only one that has run into this issue before so I am asking for help!!!

Thanks in advance
Craig