I was active on the Nat 5 threads last summer under a different user name about DS's Nat 5 computing grade. Very long story short - he was predicted at least a B, got a D, school investigated and it transpired that most of his second paper had gone missing. SQA emailed school to say they would honour the predicted B.
Well it's now almost February and it's STILL not sorted out. School were told he'd get a new certificate. He hasn't. His MySQA account is still showing the D. School has had a change of staff and the new teacher who is dealing with SQA is on the case but trying to get an answer from them is horrendous. And it's only a couple of months until the next set of exams!
So, a word of warning to anyone with kids sitting exams this year. If you need to raise an issue with SQA you need to be on them constantly, or encourage school to do the same. I had similar issues with one of my Highers which went to appeal in 1989 and it really doesn't seem that they've upped their game in 30 years.