Wabe is saying that maybe Anti-aliasing should be turned on and boosted from the default values to higher ones. Especially OAA is often needed when there is a lot of ambient light (i.e in GI or GR renders).

Excellent suggestion from Cheers & Bruno.

There is no reason unchecking or checking all render checkboxes should fix all problems. Might not be a render setting (as Cheers points out). And changing render settings values is probably what's needed, rather than de-selecting them.

My guess is that, unless you understand what each render setting does, you should use the presets and a small sample area of the scene to try to fix it (once you're sure it's a render problem - not a post-processing, material or lighting issue). 

The more i use Vue and the more i see problems in the forums, the more i'm convinced that users really need to understand the render settings and use the custom ones - and that's the only way to get the fasted renders.