Not quite the same but I registered first thing this am to submit mine and had to wait a ridiculous amount of time for the registration link to be emailed back to me.
That'll be down to Capita's software being overloaded.
What actually happens is, to save money on expensive computer hardware, they use specially bred rats in a large maze. Each one has a simple job - gnawing the punched card, carrying the card to another section, nibbling the registration code onto the card...
At this time of year they get tired out, poor things. They need extra rest breaks for grooming, so have a care and give them a break.
It gets far worse just before allocation day in March. You may have seen the article on BBC Points West last night about 'super vermin' that are resistant to poisons - well - they're the reserve that are brought in to cope with allocating children to secondary school (for entry to reception they use mice as the children are smaller). As far as I know, the rats are each given a punched card relating to a child, run around the maze until they can get into a little enclosure for each school with a bowl of food to attract them. Each 'room' only has space for the PAN of rats, so once one is full, the rats left out have to find another room.
Of course, there are inaccuracies in the system. The rats teeth sometimes make extra holes in the punched card, so the wrong child is allocated a school....And that, dear readers, is as accurate an explanation of how the allocation software works as you're likely to get from anyone. Try asking Shire Hall, and they won't tell you.