Answers to some linux problems
ACPI : CPU frequency scaling unsupported
I own a Toshiba Portégé M200 (Though it seems this also happen with other Toshiba units), It recently blew up (graphical chip fried). I sent it back to repair and they changed the motherboard. To my surprise, when It came back, the frequency was stuck at 598Mhz (Note that it did not only happen under linux). After a bit of searching, I found out that it was caused by
a configuration problem in one of the motherboard chip. You might wonder what that means, well, the motherboard seems to hold essential information for the centrino speedstep technology to work. There is no way to fix that by yourself unless you have access to
some in-house toshiba software [External Link]. Basically, I extracted the floppy image, network booted on a pxe server (The Toshiba M200 doesn't have a floppy nor CDROM drive). There in the menu, you press 2 then 1 and it will reconfigure your motherboard. (Note that it's not a BIOS problem). The only thing that remains unknown is why the technical support did't fix it in the first place....
GUI : Gnome and KDE apps are so slow to start (10 minutes)
First, you may check why it seems to take so long. start up a light window manager such as fluxbox, then do something like "strace gedit". If it seems that it hangs a long time on a network connection, it might simply be that you blocked the RPC port with your firewall. Unblock the port for local connections and it'll be back.
Printer : Cannot connect to the cups backend
You might want to check cups is running, if it is indeed running, the solution might be where you don't expect it:
check your firewall rules. Make sure they let you through to cups. I spend an awful lot of time finding what the problem was, in fact, my iptable based ruleset was preventing everyone including localhost to connect to the cups port.