This is a PDMworks Server issue - Some of the solutions I have found to fix the issue

1) Validate cleans up any errors in the vault and can Potenitally fix the issue. - Server could be in a deadlock and its just continually going through the Cache. Fix would be to restart the service with validate turned on.

2) Server log on (windows account) has an issue with the PDMworks Service. Changing the account with full rights under the PDMWorks services menu.

a) Go to Admin Tools\Services\ Find the PDMworks service (Right mouse Button) RMB go to properties, then to the Log on tab. If you are using an account there, you can change to another account and see if that fixes the issue (Must have full rights).

3) Reinstall the service (Server install) - You would need to back up your vault on uninstall the vault. When you reinstall, you should only have to point the install back to the original vault. (The Backup is a safety precaution).

With a 10GB Vault size:
Validate Off = 20-35 Minutes Varing on Machine speed
Validate On= 30-60 =Minutes Varing on Machine speed (recommended)