I would suggest upgrading to the latest WordPress Version that was released which is WordPress 2.8.5 .
It’s a security update so don’t think twice. Here is the headlines for the updates:
The headline changes in this release are:
* A fix for the Trackback Denial-of-Service attack that is currently being seen.
* Removal of areas within the code where php code in variables was evaluated.
* Switched the file upload functionality to be whitelisted for all users including Admins.
* Retiring of the two importers of Tag data from old plugins.
Source : WordPress.Org