In one Scottish seat just announced - Glasgow Anniesland - there were 1,736 rejected ballots - that's a massive 7.2% of those who voted. The level of spoilt votes in the first three Scottish declarations has been running at 3% to 5%, well above the norm.
The huge number of wasted votes is presumably because people simply don't know how to fill in the ballot paper. Scots voters are not just having two votes for the Scottish parliament - there's an utterly separate system for the Scottish local elections, and of course, there's a third system for the Westminster elections. A potential problem with the electoral process.