Installing from a .pkg or .mpkg file on Mac OS X Lion

I have a strange problem since upgrading to Lion: Some .pkg and .mpkg files won't open the installer but instead will open the terminal, and no installation takes place.
The most recent example is the Microsoft Office 2011 Update 14.1.2.

Does anyone know of that problem?

Solution 1:

The update did not work for me, as I had already run it. It broke after the update. I still had the problem. In Finder, I could see that the file extension icon was not the gold/tan box icon that goes with Installer. There are two ways to do this. 1) In Finder, right-click, or get to the property window, and "Open With" and navigate to /System/Library/CoreServices/Installer.app. There is a checkbox to always open with this app. -or- 2) Open Installer itself and drag the mpkg file into it. Run the installer.

Both of these should run, and also change the mpkg icon in your Finder.

Solution 2:

Ha, I thought I'll have a look if there is a new mac osx update and—"yes!"—Mac OSX Update 10.7.1 solved the problem.