As already posted in another thread the installer that we downloaded tonight it's actually working for 3 of us (the average was infact based over 5 peoples!), just the Leopold (10.5.5) usrs is still looking for where the firewall option have been put!
However before to claim that the installers was corrupted we did tried all the follows:
-Restart
-Redownload
-Cleared Old Package & Libraries
-Disk Utility
-Consolle installation
We didn't tried to switch the account since we were all admin but as it works now there's no need anymore!
Thank-u for the advice (could b usfl 4 a nextime) and sorry for the ironic answer (but the one U gave me in the begin wasn't very helpful!).

Peace, Love & Aeternal Life
DKK