The following consists of two blocks. The inner block should be bottom aligned.
For some reason, we are completely losing the inner block. It would appear to be a problem with the solving of the equation given in section 10.6.4 of CSS2. All the vertical properties are given (all as 0 except for 'height' which is given as 1em) except for 'margin-top' which is auto.
Note that if the height of the outer box is explicitly given, everything is ok. So it seems we are not getting the height of the outer box correctly when solving the equation for margin-top.