Hello All. I'm facing the same problem on my Dell latitude D620 GMA950(Centrino Duo, 2GB DDR2 RAM, Intel Integrated Graphics 256MB, 120GB HDD). It fails every time with the same message: "Install Failed, the installer could not copy the necessary support files". The only basic difference is that, I'm trying to install Retail SL 10.6 on an External Hard Drive which has GUID partition table. I've tried more than 10 times, by restoring the SL DMG to USB through the Disk Utility and every time it fails after copying 2 files(iChat.pkg and index.product) which goes for around 5 minutes and it fails. For all these attempts I'd used the D620SLV01 bootable CD. I also tried using the customized bootable USB image as mentioned @http://www.osxlatitude.com/creating-a-usb-pen-with-osx-installation/ but that also failed with the same error message. No idea whats going wrong.
Would highly appreciate if someone can help me fix this problem. I've been struggling on this for more than 2/3 weeks. Thanks a ton.
This is the screenshot of the "Install Failed" message: http://img339.imageshack.us/img339/7337/20120211140106.jpg