Scottish Executive ultra vires in Adoption Act?

In Today's Sunday Times (perhaps only the Scottish edition, I'm not sure) there is an interesting slant on the 'gay adoption' dispute. Last year the Scottish Parliament passed the Adoption and Children (Scotland) Act under which Roman Catholic adoption agencies were granted the right to refer homosexual couples to other agencies. Readers will know (specially if they have read this) what my views are on this subject; I won't go over that again.

However the Sunday Times article includes an interesting comment: "However, because adoption is a reserved matter, Westminster can override Scottish legislation.". Now I am not a constitutional (or any other kind of) lawyer, but it seems to me that the premise of this analysis is fundamentally wrong. My reading of what that implies is that in matters which are 'reserved' to Westminster the Scottish Parliament does not have the right, under the Scotland Act, to legislate. Period. Presumably the House of Commons/House of Lords (i.e. 'Westminster') could grant the Scottish parliament specific powers to legislate in reserved matters either by amending the Scotland Act, or by some other kind of mechanism, but so far as I am aware has not done so. Mind you that would not be the only occasion that the terms of the Scotland Act have been flouted by the Scottish Parliament, with nothing being done at Westminster to rein the Edinburgh 'cowboys' in! (see [*] below)

The situation is not, so far as I can see, in any way analagous to the cases where the Scottish Parliament has decided to allow the Westminster parliament to legislate on its behalf in matters which are devolved to it under the Scotland Act; as for example happened in the case of the Civil Partnerships Act and a few other cases since the Scottish Parliament was legislated into being by the Scotland Act.

[*] - The specific case I am thinking of is the clause in the Scotland Act that covers representation by MPs from Scottish constituencies at Westminster and projects a reduction in the number of MPs from Scotland some years after the coming into being of the Scottish Parliament (and which will take effect at the next Westminster general election, probably in 2009 or 2010) from the current 72 to 59, to take account of the fact that many areas of Scottish domestic legislative powers will now be devolved to Edinburgh. That reduction in Westminster representation from Scotland was supposed, under the Scotland Act, to have resulted in a parallel reduction in the numbers of MSPs at Edinburgh from 129 to 108. However, MSPs voted a couple of years ago to ignore this and to continue to ask the Scots to continue to pay for the additional 21 MSPs, despite the fact that this flouts the terms of the Scotland Act. So far Parliament at Westminster, likewise of course our sorry excuse for a British government, has declined to tackle this affront to its authority and the Labour government seems unwilling to [further] jeopardise its electoral prospects in the upcoming (in May 2007) Scotish Parliament elections by highlighting the matter.