This time around, I broke my own rules in waiting at least one month before updating Ubuntu.
8.04 LTS was released in April 2008; I installed it soon after that, because it absolutely would not install correctly on a Thinkpad T61p; and then I got a good install with the 8.04 LTS July refresh.
Did you try re-installing Evolution? And what happened if you did?
Also, it's a pain, but consider entering bug reports on Launchpad
https://launchpad.net/ubuntu