I am getting the following error on some machines when they attempt to update:

Update error
Severity: Error
Application: Kaspersky Anti-Virus 6.0 for Windows Workstations
Version number: 6.0.3.837
Task name: Update Task
Computer: xxx
Group: xxx
Time: 01 November 2009 11:40:14 PM
Description: Update error: Bases are incompatible with application,bases have been rolled back.

Has anyone seen this error before and/or can anybody make recommendations to fix this?

Thanks