I've been using Stratum since I went back to mining for this pool, so far so good.
However, there's something that has piqued my interest... with over 10k submitted and accepted shares, I see the rejected share column has Stale/Dupe/Other. In my case, the count is 20 / 0 / 3 which I suppose is rather decent. Now, what are these "Other" rejected shares? I skimmed over both threads and didn't really see the answer to this question, so it would be nice to know whether I should be concerned or not.
Other = Unknown work OR Low Difficulty.
Unknown = This is generally the result of the server being restarted. The server keeps track of the work it has sent out for the last 5 minutes [10 work lists]. When you submit a share, it checks if the work list exists. During a reboot, these lists are wiped/start over. Additionally, your ExtraNonce is changed after a server restart.
Low Difficulty = You likely submitted a share at the same moment as your difficulty was adjusted upwards, almost like a stale. The next major revision to the Stratum code will be altering how difficulty is handled to allow work submissions of previous jobs at your old difficulty. At the moment this isn't high priority, because this generally only happens once or twice during your first minute of being connected, and frequently it won't happen at all. The variable difficulty implementaion on BTC Guild is very elastic, so it does not constantly bounce you up/down between difficulties after you've been adjusted up.
