I'm pretty new at this but it is my understanding that when you import a snipe(i.e. import it from your Ebay watch list) it automatically sets a bid for you in the snipe settings. If you then click ok to import the snipe(s) it is entered as a snipe ready to be entered at the default time of 5 seconds.
Did you import any other snipes from your watch list? If so, perhaps you accidentally added this one as well without noticing.
I can't help you with the lack of "bid too low" notification or the missing item in your list.