If you are running any version of PostgreSQL 7.4, 8.0 or 8.1, it is now time to upgrade to 8.3 or 8.4. The versions 7.4 and 8.0 are slated for end of life at the end of this month. The 8.1 version is slated for end of life in November.
This is not an item to take lightly. Once a version is end of life you will not be able to get support (easily), there will be no more security updates and no bug fixes even if they are data loss bugs.
I often find it disturbing how many people will run older releases. I am not talking about someone running 8.2 when 8.4 is out but we still see the occasional post on the lists about someone running 7.3!
Remember folks, at a minimum keep your dot releases updated. The community does not release dot releases on a whim, it is for the protection of your data.
Of course, if you need any help with upgrading don't hesitate to ask.