Any system logs search displays the output twice. The displayed data is the same. Screenshot: http://screencast.com/t/kGrrYAZ1 We have tried Koha 3.5 and 3.4.4 -same issue. On 3.2.05 it works okay.
I believe this bug will be fixed by the patch for bug 6460. It actually does the exact same thing I was going to do (and fixes a couple of other issues with the logs as well). Thanks for filing this!