I have found a weird issue when playing multiple FLV files in sequence. It looks like some of the colors have a vertical shift of around 8 pixels. It seems to depend on the video dimensions.
I tracked it down to a situation with two very simple files. Please download 1.flv and 2.flv.
When I play 2.flv only, I see a blue screen with a black bar at the top as intended:
However, when I put both 1.flv (one black frame, but only the dimensions matter) and 2.flv in the play list, 2.flv displays with a strange dark bar near the top of the blue:
The dimensions of the application window are different between these two situations: 4 columns and 2 rows smaller in the weird situation.
Version 2.1.5 did not have this issue. It happens in both 2.2.0 and 2.2.1, x86 and x64 versions alike, with default settings.
Hope this helps!