I've removed Windows 7 from my Dell Latitude E6500 laptop & installed Ubuntu 10.10 which worked great out of the box but when I shut the laptop lid, the machine goes to sleep but when I try to use it again, I can't wake the laptop up from sleep. I can see the illuminated keyboard light up but I have to manually hold the power button down to shut it down and start it back up again from scratch.

Can someone please tell me how to get this working like it did in Windows 7 or at least get the machine up & running.

There's some weirdo config option in the kernel which protects the bottom 64k of memory from being written to by processes. It sounds like you need it. I can't tell you where - I think it was early on in the config, but I've spun through in a hurry twice or three times recently. To hibernate, select swap as a resume partition, and boot with 'resume=/dev/sdax' where x is your swap partition.
cat /sys/power/state - should have mem disk, meaning you can suspend to memory or disk
echo -n disk > /sys/power/state should hibernate. Likewise for mem and suspend.

Thanks but I couldn't get it to work and swapped this out for a MacBook Pro...