Installing Motu Mach Five Software


i am trying to install motu mach five sampler software on my g5 . when i use easy install the installer stops and gives me a message
that reads
error creating folder
1008:9-5000 Access denied error
can anyone help here. i can use the custom install and that works except the Application uvi-xtract that comes with the programe does not get loaded onto the computer.
g5 dp 1.8 3gbram osx 10.4.2