"I also remember the Scottish devolution referendum where people voted against that particular manifestation because it didn't go far enough, and were then told that they had voted against devolution in any form."

Quite so! In fact it goes further in that they were told by a Scottish ex-prime minister (ie Douglas-Home) to vote against because the Conservatives 'would' introduce a better type of Assembly than Labour were proposing. Although the YES vote were in the majority it was not a big enough majority as they'd said it needed 40% of the total electorate to carry it. I imagine that at least some of those who didn't vote didn't do so because they believed the Tories were goign to introduce a better deal anyway!