Panasonic CF-52 Toughbook
Anyone trying to install on a toughbook model no cf52D***** or cf52C***** may find that as the kernel tries to start the laptop freezes. I have managed to get around this but in the process I have sacrificed much of my acpi support.
In order to get a distribution to boot or install you need to pass the acpi=ht or acpi=off instructions as boot options. Although this allows Linux to install/boot much of your acpi support is lost. For example after a shutdown you will have to manually power off.
As far as I can tell it is something to do with the BIOS but I am not in a position to diagnose any further. Although I have logged this as a fault with Panasonic I am doubtful of a helpful response.
Its a pity as they aren't bad laptops. However if you're looking to buy one my advice would be don't, get something more supportive of Linux from a company who are more receptive to the open source community.