On Stack Overflow we see a lot of "answers" to old questions that are of the form:
Have you got a solution for this yet?
Usually where the question has no other answers.
This, of course, has the effect of bumping the question to the home page where it gets more views and might even get a real answer.
It also has the effect of causing the answer author a temporary loss in reputation due to the down-votes it inevitably receives (until the answer is deleted) and, more importantly, NAA flags which we mods have to clear up. If the user does this enough they'll even end up with an automatic answer ban due to the number of low quality deleted answers they have provided.
To stop the bad behaviours but still retain the possibly beneficial bumping would it be possible to have a "bump" option on question. This will add the question to a queue and if it gets enough bump votes from other users Community will bump the question.
Obviously a user can only vote to bump a question once, or at least once in a long while, to avoid people continually trying to bump the same question.
I'm not sure how many votes would be required to initiate the bump, certainly more than one, but certainly not too many otherwise the option would be virtually useless.
Also, we'd probably want a "I'm having this problem too" button right next to the "Answer" button (thanks. Christian) as it's most likely to be new users unfamiliar with how SE works who add such answers. By putting the option right in their faces we should be able to get them to use it rather than the answer box.