I should add to this; I have come across keys that have not worked that I have definitely not used, and after contacting support for the bundle site, they have emailed me keys. Most major bundle sites have very good support. Speaking of which, IndieGala has failed to get back to me about not getting an extra happy hour bundle, so I'll have to hound them again. In the past they have given me an extra bundle or two when they have stuffed up. In this case, it might be my error as I may have had the page open for ages before purchasing the bundle.
Well said, +1! Oh hang on, that's me talking to myself again :P
Follow-up re IG support. It was my error; I had left the bundle page open and purchased after happy hour had finished. Indie Gala's response to my second message to support? Sorry you were wrong but here's a free bundle anyway! I feel bad for getting something when the error was mine. Their reason for a free bundle? Because they failed to respond to my first email, which was a first for them.