Has anything on that server changed - anything at all (software updates, security updates or patches, new software, network configuration or domain login policies, change of permissions, etc.)?
Check and make sure that the server has plenty of free drive space. If you can provide the exact error message, and if possible detail from the system logs, along with the name of the package and the MD5 checksum of the package as it sits on that server, this may help us determine what the problem is. We may need additional information, but this is a start.
We have not had any other reports of similar behavior, so at present, this seems like an issue related to the OS or server itself. Possibly the gremlins that roam the ethernet, but I won't blame them just yet.
In any case, a few things to check, and then we can take it from there.
