FFTactext only works on clean iso?

[rnorphling]

Hey there, I want to know how does everyone edit a patched ISO. I would like to rename some skills on a fft1.3 iso but everytime I click patch ISO it failed and said DTE for OPEN.LZW failed. I didn't even touch OPEN.LZW, all my edits are on WORLD.BIN.* .
But if I start from a clean ISO, done my edit, and patch then it works. Any thoughts?