Curious to know why you didn't just install 11.10 directly ? Since
it's evidently a new install I'd suggest trying again with 11.10 from
scratch - in theory a clean install of 11.04 *should* have upgraded
well but we all know that theory and practice don't always match !

J> I was a little surprised to find my machine became extremely slow
J> once I installed Ubuntu ... 11.04, and immediately upgraded to
J> 11.10 ...