I've revisited this thread, and a thought occured to me with regard to tech questions.
Although the initial query was answered, there may be secondary points that arise, and discussion of these could be of benefit to members.
I agree that repeated postings of the same solution are of no benefit to members.
The problem is that the secondary points are buried deep inside these threads. There are threads with 100+, 200+ pages, which not many people give a second look. Unless it is a thread like the Wall Observer thread in Speculation, it is best to lock these threads.
Secondary points can be brought out in new threads. I would prefer that to having a spam thread which goes on and on.