I think there can be many reasons for a miltilink group to fail. Remember that multilink is negotiated by the two parties at link setup time, so if they do not reach agreement then you don't get multilink. If one end tries to add a link to the group and provides daft parameters, I suppose make it fail in some circumstances.
The best way to tackle problems like this is show debug ppp negotiation, and/or debug ppp multilink events and see what actually happens.
Kevin Dorrell
Luxembourg
