part of the problem is users don't know to CLOSE their questions when they get an answer, and I think that that issue will be true for having feedback areas too, many people get their answers, say thanks and forget about it leaving their post indistinguishable from unsolved ones (I do this too!!)

I think you should have an option that the question creator can mark for UNSOLVED to signify that they have not got a satisfactory answer.

once flagged you could have a special section for looking at them.

in order to clean out such a section you would have to have a rule like "The responsibility lies with the creator to remark the question us unsolved else the flag will dissappear 2 weeks after the date of the last post" or something, else the section would become the same as the current situation.

many advanced users would like an area of unsolved posts. and if you made it so you could not post directly to the unsolved section the interest for the problem solvers would be held as only genuinly unsatified people would be there