Can't install any applications via Installer.app!

[ghostlines]

I've noticed that I can't install any apps that are installed via the installer app.
I can drag and drop apps fine. But apps required to be installed via the installer app, give me the following error:
"an error occurred while evaluating javascript for this package"

This blocks me from being able to select any volumes at all to install my application to. I googled around and heard that it's a volume check error.
And that i should remove the volume check code lines in the packages. I did this and successfully installed 2 apps, the Iphone SDK, and the Iphone configuration utility.

Now I'm trying it to install Safari 5 and this method isn't working with it at the end of the install i get a script error.

Any Idea's why I'm not able to install packages anymore via installer.app?http://g.media.macrumorslive.com/f/smilies/confused.gif
Any help at all is appreciated.

I'm running OS X 10.6 on a unibody macbook

 

[ghostlines]

Got through to install safari 5 it seems. Even though i got a script error at the end. Though I still didn't install it the normal way, i had to open the package with packagemaker.app and remove the installation requirements. Then build and install it.