Maybe your web front ends are out of sync.
RDP to each of your front ends, and place a JPG in the 12 hive. The picture should be the number of the web front end respectively.
In the list/document library's dispform.aspx file, use SPD to reference the JPG from the 12 hive using an HTML tag. When you view the page, it will show you what web front end you're looking at.
This way you can see which web front end has the syncing problem. If...that's the problem.