I'm more likely to hit a problem like there's not enough of the shot or the shot had some annoying issue (someone moving in the background, or weird camera angle that doesn't fit with the clips either side) or horrible colour (ugh, horrible colour!) than that it isn't there at all. So please don't think I have problemless clip sourcing! I wish it were so... my current vid is kicking my ass with lack of or boring looking source footage.