Thanks for reporting that! We'll dig into it to get it resolved as soon as we can.
For the public forum - we've sent Chris a hotfix and are going to roll out a Beta 2 of 5.1 with this fix and other issues. As always, thanks for folks using our beta versions!
I think I found an issue in VistaDB 5.1 Beta (188.8.131.525).
When I do a query involving multiple dates in the Where clause zero results are being returned instead of the expected result.
The same queries run under VistaDB 184.108.40.2068 return the correct results.
The attached file has the queries above plus example database.