Unless you are using a configuration file you should be careful executing the install using PowerShell. Reserved characters in PowerShell might be messing with something you are not expecting. I know for me on more than one occasion I gave up trying to run the install from PowerShell when $'s in passwords and named instances were being interpreted as PowerShell variables.

Edit: Sorry, just noticed you are using a configuration file for most of your settings. If you are using a dollar sign anywhere you might need to escape it for it to be interpreted correctly.