Yeah, I think there should be at least a written rule somewhere. I personally don't have a problem with people bumping up old threads. It can be kind of annoying, but it doesn't bother me. But, since it's obviously not appreciated by all, a rule would be nice.
__________________my name is ashlee
"I can feel it - the turn of the Earth,
the ground beneath our feet
spinning at a thousand miles an hour.
And the entire planet is hurtling around the sun
at 67,000 thousand miles an hour and I can feel it.
We're falling through space, you and me.
Clinging to the skin of this tiny little world
and if we let go..."
- The Doctor