Well it's going to be the first time I do not recommend updating WordPress, and that version 2.8 is showing some inconsistencies especially in updates.
As you know, I havefrom the first development version, and I have to say that in new installations it is not giving me any problem, but the thing changes in updates. I do not know if it will be from the updater or something that has been introduced in the final version.
In the WordPress Forum we have enabled a which, of course, You can also comment here. Also on the official support forums they have a FAQ for problems with WordPress 2.8 . If you want to be up to date with no problems, just now it is safest to continue with WordPress 2.7.1 which you can download here .
Having seen these problems, right now I do not recommend upgrading to WordPress 2.8 it's almost better to wait for version 2.8.1 where I'm sure these specific but annoying problems will be fixed. And yes, it does not happen to everyone, but remember that a web is like a computer many variables affect it.