Hi,
I assume you have never experienced this error before? Are you experiencing it any longer?
From your error message, it appears that while your program caught the error when attempting to write to the database, the error actually occured somewhere in your test steps. What would have caused your tests to "stop" generating data? What made you ask about daylight savings time - did your tests begin generating data again after the "jump back" hour (for instance, did your tests not work for the second 1-2 am hour but begin working again afterwards)?
Since I'm not sure what kind of data your application is logging, I'm not sure what could have caused this error. If you are taking timestamped data then perhaps your tests did not like data being generated with the same timestamp and threw an error. What kind of tests are you running and what language are they written in?
If you could give me more information, I'd be glad to help you out.
Matt M.
NI