  We study aspects of the new phases of M-theory recently conjectured using
generalised dualities such as timelike T-duality. Our focus is on brane
solutions. We derive the intersection rules in a general framework and then
specialise to the new phases of M-theory. We discuss under which conditions a
configuration with several branes leads to a regular extremal black hole under
compactification. We point out that the entropy seems not to be constant when
the radius of the physical timelike direction is varied. This could be
interpreted as a non-conservation of the entropy (and the mass) under at least
some of the new dualities.
