Issue with installing provider hosted app by using PowerShell

Hi 

My provider hosted app (MVC) works just fine if I installed it in a web by using "Add an App" button, however if I install it by using Import-SpAppPackage & Install-SPApp command, the code will throw access denied exception every time trying to instantiate ClientContext of the host web. Is this a limitation from the powershell command? Also the other issue with this PowerShell command is that event receiver in "App Install" event won't get triggered.

Thanks.