Visitor Segments show NO data after refresh


We have been using Piwik for about 8 months now for our production website. Ever since the auto-upgrade to 3.0.1, we can run a saved visitor segment or create a new visitor segment and the first time it runs, it appears to return all results correctly. However, if we refresh a segment that previously returned good results, then the same segment returns no data. We can then create another segment with the same filters/criteria, and again, the first time the data is returned, it looks fine, but upon refresh, all data disappears. Please Help!!