weird render thing

[Anonymous]

I'm sure this is a Mavericks related thing but here it is.  I have a moving video on V1 (helicopter shot).  On V3 is a gap with text effect keying over background.  If I move the text effect a few frames one way or the other, I need to rerender, however some of the old render has stuck, meaning, when the timeline plays through the title, the background clip jumps because I've slid the gap text 4 frames back so there is a 4 frame jump in the background that reflects as if the background clip was baked into the render of the gap text effect.  Yes, I can flush the renders and rerender and it's fine but still...