For the past couple of years now, it seems Sinn Fein have been urging other parties to live up to their obligations under the Good Friday Agreement, including the DUP who never accepted it in the first place. However it seems slightly disingenuous on their part, given that they don't really live up to their own responsibilities, namely the acceptance of the consent principle and Northern Ireland's right to self-determination.

Follow up:

This is why it came as no surpise when I read on Slugger that a motion was passed on the first night of their annual conference calling for either "neutrality", ie the end of the policy of Union Flags flying from government buildings or "equality", defined by Sinn Fein as flying the Irish tricolour alongside the Union Flag in such circumstances.

"Where there are British cultural symbols involved in public life in the north, equivalent Irish cultural and political symbols should be given equal prominence. If agreement or consensus cannot be found on this then a reasonable alternative is to suspend the flying of flags until such agreement can be found."
Alex Maskey Motion 39, Sinn Fein Ard Fheis 2006

This is a simple propaganda exercise, and not really surprising. It is not an issue of equality or neutrality as Sinn Fein suggest.

Equality
The proposal to fly the Irish tricolour alongside the Union Flag is a non-starter. The issue here is not equality, the motivation is purely and simply to undermine Northern Ireland's legitimate position in the United Kingdom, by trying to give equivalence symbols of the Irish Republic, thus implying a sovereignty which doesn't exist. As long as Northern Ireland is a part of the UK, it would be completely wrong to fly the flag of a foreign state on any government buildings and an insult to the principles of the Good Friday Agreement.

Neutrality
Simmilarly, it would be inappropriate to run around removing any symbols of British sovereignty from Northern Ireland. Sinn Fein may not find the situation ideal, but in signing the Good Friday Agreement they have accepted it on the precondition that it is the will of the majority of the people of Northern Ireland. They should therefore act accordingly, instead of trying to erode that sovereignty using the mask of 'neutrality'. Besides, if they were genuinely interested in neutrality they would surely be willing to discuss creation of a new 'neutral' flag for Northern Ireland. As Babs Brown explains, they are not.

"To force me to say i am in favour of a flag for a piece of territory that people in my community don't identify with is itself problematic because what you're trying to do is to force me to a common view that is not common, or to pretend there is a common view when it is not common."
Bairbre de Brun, Sinn Fein

Cherry-Picking the Agreement
So what we have is a situation where 12 years on from the agreement, Sinn Fein are trying to go back on their word because they already have what they wanted from the process (ie the release of terrorists and fat MLA salaries).

This is not a new phenomenon. Since the agreement was signed it has been clear that republicans want to cherry-pick the parts of the agreement they agree with, gain the relevant concessions, and do little or nothing to recognise the rights of the unionist people. They signed up to recognising the legitimacy of Northern Ireland (as a constituent part of the United Kingdom), as long as a majority of the people here want it that way. It ill befits Sinn Fein to lecture others on fulfilling all aspects of the agreement when they have singularly failed to fulfil even the most basic of promises they made when they signed up.