...on gossip, or is it?

Whether or not you believe the Christian viewpoint that gossipping is sin or not doesn't really matter, surely you believe that gossipping serves no good or useful purpose?

So then, what is gossipping and what is not? I'm not talking about the obvious, "..she said that he was going to do it and he didn't, she's such bitch..." etc, but the grey area when you chat about other people without really intentionally being nasty.

Let me give you the specific example which started me off thinking about this. I trust that if you know anyone involved here then you will respect them and not gossip about it!!
The situation is over a colleague at work. The team in which I work does not work closely with them normally but one particular thing I do involves them heavily. This particular person is not the best at their job and makes mistakes which my team often has to clear up after them.
So, when we talk about this person in relation to this particular bit of work and we moan that they're not very good, at what point does it become gossipping?

Thoughts?