Had an order in with HSBC at yesterday's close which wasn't filled. At about 4.15pm I cancelled the order. For the next half hour or so it sat there saying "Authorising", after which I logged out and forgot about it. On other occasions where it's said that, it's soon gone through and gotten cancelled.
This morning after opening I thought I'd check that stock again to see if I wanted to put in another order. Much to my surprise, the order was still there and partially filled already. When it finally went through, I checked for the contract note and found two other contract notes for the stock, both of which said that they cancelled my order confirmation for the stock (partial amounts in each note).
Don't know what's going on there or what those cancel notes mean (I'll have to ring them later), but I'm happy with the order, so I hope it doesn't just suddenly disappear on me when they realise something's been stuffed up