Bug candidate in Lua 5.1.2 ?

["G.H." <code933k@...>]

Hello everyone.

I am pretty curious about this because it looks weird.
You'll see, it appears to be that table.remove() isn't
working properly in Lua 5.1.2 or, at least, it has
unpleasant "secondary effects" when modifying values
previously assigned from _different variables_ :

a = {3,7,8}
return #a
3
b = a
return #b
3
table.remove(b, 1)
return #b
2
return #a
2

I have tried in two different computers obtaining the
same results. Any ideas or teachings about this?
I hope it'd be my imagination...

Thank you in advance -- Mario