Why questions that have been answered by me or other people are being bumped by 'community'. I see a lot of questions that have been answered correctly, just the person asking the question didn't marked it as solved. Answers given to the questions cover everything there is nothing else to be said.
I've asked this question before after seeing questions pop up to the top wondering, "Who drives the Community ♦ login in and why?" The answer I received was thus about the questions popping.
Community is a completely automated process. It looks for questions which have languished on the site and moves them up to the top by modifying them slightly (or updating the "modified" time in the database), which then pops it to the top. What Community considers as a question which has languished is one which hasn't been answered. To be considered answered by the system, it requires one of two things. First (the obvious one) is when the OP selects an answer as "thee" answer. Second, independent of the OP's selection, if a single answer has been upvoted. As per this Meta.SE answer:
Note that the posts eligible for bumping are those scoring >= 0 that have gone at least 30 days with no activity, have at least one non-deleted answer scoring 0 and none scoring more than that, and no accepted answer (also, they can't be deleted or closed).
If a Q/A meets these criteria, Community views it as fair game and will bump it.
So, one or several of the questions you've answered have been clicked to the top in this manner. There's not much we can do about that now. What we can do about it going forward is to ensure we are voting on not only questions, but answers as well. I realize we cannot vote on our own Q/A's, but we can vote on others', so I encourage all to use up their (up to) 40 votes per day. There is lots of content on the site which deserves it ... if it's points you're after personally, voting on other people's stuff brings votes your way. I don't know why it works that way, but it does (well, good answers help here as well :o).