I have some 30i 16x9 clips in a 1080p29.97 project / sequence. Before I upres the SD clips, I'm wondering about this. I noticed on some SD clips I've continuously been adding effects to, removing, adjust, back-and-forth, some of the rendered sections have seemed to go bad or sort of glitches out. Nothing is wrong with the master clips, but once in a while I see this happen after doing a render on a clip.
Would it be beneficial to delete all my renders and start fresh? Is there anything negative about this, except that I'd have to obviously re-render everything? Then do my online uprezzing?
I have also noticed sometimes I get the annoying "General Error" message upon playback of some rendered clips and have to re-cut those sections back in. Again, I know there is nothing wrong with the SD master clips because I've been working on this project on and off for a couple years and this is a very very new occurrence.