For various reasons the permissions on the hard drive can get corrupted and Logger Pro won't install. Typically this will manifest itself with all the options in the installer ("Application", "Sample Movies", etc,) being grayed out, and instead of an "Install" button you'll get a "Skip" button.
1) Open the Disk Utility (in the Applications\Utilities folder.)
2) Select your partition in the upper left frame
3) Click the button "Repair Disk Permissions"
It takes about a minute to run, it will probably find some things...
4) Try to install again.