Firstboot script package no longer installing

Super productive day yesterday after reading up on some of R. Trouton's new firstboot script goodness! Built a 10.7 image - noticed a few bits I could polish up, did so - and re-ran the build. Now, can't seem for the life of me to get my first boot script to install as part of the build any more. Permissions, and files, are identical to what they were prior to my messing about - and I -was- able to build at least 1 image with this updated package - just can't seem to do it a second time. I'm testing on a partition and have checked out the drive contents prior to rebooting to it and can't see the scripts or launch deamon. Totally odd - literally everything else (including files in that same catalog) are installed properly. I'm assuming that I'll find my mistake today - but just in case - are there any InstaDMG related caches that I should clear out just to be sure?