[MikeKL]

I've spotted an issue where sd deinterlace may not get the double rate output when "sync playback to display" is enabled. Disabling that options avoid this.
HD deinterlace doesn't suffer from this (it occurs when deinterlace runs too fast and both frames are displayed in the same vsync).

If you use deinterlace please report back. Even if it is "everything is okay".

Everything appears to be visually OK with my DVB-T SD content, in sense that I don't notice any obvious difference in Picture quality with De-interlace settings set to auto, "sync playback to display" enabled or disabled.