Ubuntu :: Cannot Hibernate After Adding More RAM To Netbook?

I'm running Ubuntu 10.04 (Lucid) and I recently upgraded the amount of memory in my Acer Aspire One A110 netbook from the default of 512M to 1.5G. I don't use this netbook very often and only today after I was done with it did I try to put it into hibernation rather than shutting it down and discovered that the option was no longer there.

I googled for a bit and then realised that I didn't have a swap partition. I don't know if I ever had one or whether I was using a swap file, but I followed this guide to create a swap partition, which I can now see. I also followed the bit of the guide that talks about making the swap partition work for hibernate, but although I can now see "hibernate" in my power menu, if I select it, the disk thrashes for a bit but nothing happens.I've tried running

Code:
sudo /etc/acpi/hibernate.sh
from the command line in case it gave me any error message, but it doesn't, and neither

[code]....