From time to time, users post the same request in two or more sections. I myself think this is OK. They're more likely to get their answers that way.

Though I do think it would be handy if the user, or moderators, could link two or more theads together.
It would necessarily do much, but at the top of each thread could be something saying that this thread is linked with another, or vice versa.

That way when replying people could check the other replies first etc...

... just an idea