Installer can't "write the receipt"????

-Mac book pro 2.4 GHz Intel Core 2 Duo Mac OSX 10.5.4 4 GB 667 MHz DDR2 SDRAM, bus speed 800 MHz external HD LACIE 500 GB FireWire 400 MBOX2 with PTLE 7.4.2 Please help me, I was re-installing PTLE on custom mode after getting an error during the previous installation (something wrong with a "/"....) so I first re-installed only the "application files" and went fine..but when I tried to install "digirack plug-ins" and "freebombfactory plug-ins" the instalation fails saying "THE INSTALLER COULD NOT WRITE THE RECEIPT FOR THE PLUG-INS"....Core audio was ok, so I opened PT and entered my authorization but I don't have the plug-ins!!!!!! I've followed the troubleshooting infos I've found here step by step (settings,screen,disabled ports,airport.....everything) and now??? Please answer ASAP, I had 10 days of madness with this MBOX2

Ok, try this - go to MacHD>Library>Application Support and trash the Digidesign folder, then do a clean uninstall/reinstall of Pro Tools. Hopefully that will clear up the problem.

"clean" means custom or guided???

"can't write the receipt" pt.2..... 

"Ok, try this - go to MacHD>Library>Application Support and trash the Digidesign folder, then do a clean uninstall/reinstall of Pro Tools." I've done, still doing the same thing......I'm goin' mad on this ....doesn't work so I DON'T WORK.