What caused GWYNETH PALTROW and CHRIS MARTIN to Consciously Uncouple?

It apparently was NOT infidelity.  Because sources say they had an OPEN MARRIAGE . . . and both of them took advantage of that.  Keep in mind, this info is leaning more tabloid trash than proven facts.

Chris Martin of Coldplay has been linked to Kate Bosworth, Helena Christensen and Kate Hudson.

Gwyneth has reportedly spent “quality time” with Glee  producer Brad Falchuk, a billionaire named Jeffrey Soffer and attorney Kevin Yorn.

If it wasn’t the typical cheating scandal that ended their relationship, what was it?  The odds seem to be on Gwyneth's NAGGING.  "Us Weekly" says they fought a lot about how to parent their kids and what to feed them.

As you probably know, Gwyneth is all about her macrobiotic diet, and a source says she frequently MOCKED Chris' eating habits.