Concern about possible conflicts between research sharing policies Funders, publishers, institutions and others are increasingly moving towards policies that are aimed at sharing research.

The degree of openness &mdash; and other stipulations in those policies &mdash; vary quite considerably, so some sort of conflict between policies of a researcher's institution, funder and publisher or between those of collaborators is to be expected.

How much should a researcher be worried about these sorts of conflicts?  Are there examples where sharing policies that differ have turned out to conflict in a way that actually inhibits the sharing that they were intended to enable?

This question was originally posted on the Open Science SE private beta, due to be closed tomorrow.
From a UK standpoint, I've yet to see an example of two open-access funder/institution policies that fundamentally conflict with each other. There is a lot of variance between them in details, and some are more stringent than others, so you could certainly do something that would be enough for Policy A but not enough for Policy B.

However, it's very hard to think of a situation which would be required to comply with one but also prevent you from complying with another. 

The main problem in practice is not that they conflict, but that they're all subtly different and they ask for subtly different things. This increases the reporting burden on institutions/researchers who may have to demonstrate compliance with subtly different policies, and provide almost-but-not-quite identical reports to different funders. It also increases confusion among researchers ("which policy applies here?"), and can understandably lead to frustration. More friction, more indirect costs, more headaches for all concerned...

On the plus side, there is definite interest in convergence. I strongly suspect that within a few years, we'll see more funders adopting a standardised OA policy (perhaps one of two or three versions - all-Gold, green permitted, etc), which should help solve this issue.