There have been a number of claims to Rockall over the years. I'm not a political person but it erks me when misinformation is spread, such as the need to re-assert Britain's claim under the 1972 Rockall Act.
As reported in the Irish Times in May 2010, the Irish Minister for Foreign Affairs Micheal Martin has confirmed that "...there is no dispute between Ireland and Britain over Rockall". Ireland is [however] pursuing a disputed seabed claim to the Hatton-Rockall area, but Irish legal opinion suggests that jurisdiction over the rock does not confer any advantage.
To further prove the point, here's a map taken from Ireland's submission to the UN Commission on the Limits of the Continental Shelf. The Rockall area is clear as an orange blob well within the UK boundary.
I hope that clears things up!