This happens to me ever so often.
I'm about to contribute a profile change and when I go back later and check my contributions page, one or some of them may say "Incomplete Submission". This is due to some connection error, I'm guessing.
I've figured out that if you pay attention and the server takes a couple of seconds extra to respond when you click "submit", your data will not be sent correctly.
You will have to go back and click on submit again. The confirmation page needs to load immediately for a contribution to go through.

However, if you're in a hurry or just doesn't pay attention, you may have your contributions not going through.
That's more of a problem to those of course who makes loads of contributions. And if you have flagged a lot of profiles to contribute at once.
Still, it's annoying and I've had this problem a long time now.
I'm using Firefox, if that's helpful.

I can confirm this problem. Haven't seen it lately, however.

Quoting T!M:

Quote:
I can certainly confirm this. Initially I wasn't sure whether it was just me, for a while I thought it might have been some bug at my end. It pretty much happens to me a few times every single day, including today. Mostly a second attempt will make it through, but on occasion it has taken up to four or five tries.

So I guess it's a server issue then? Like a broken connection or bad "handshakes" or ping, or what I should call it (I'm no expert in networking).
Or some software issue on the server.

Not as serious as your average BSOD, but if you're on a roll and "mass-contributing" say 50–100 titles, it can really screw things up. And give you gray hair.
I would really appreciate a "waterproof" system that doesn't mess with your contributions. Time is money, and all. You spend enough time making sure the data you contribute is without errors, so being given extra work isn't exactly welcome. And not to mention that if you have to do things over again you may make errors in this second attempt, if you have to go back to a not-so-recent contribution, if you failed to notice that your contribution didn't go through. The only way to see this is to check your contributions page.
At the very least there should be a "There was an error" page with your contribution if it didn't actually go through.