During the entire life of my TS2010 installation and, up until a couple of weeks back, with my current TS2012, CM and the Trainz portal would not comunicate except by using the 'change password' trick.
Of late, everything was performing perfectly and I assumed that N3V had fixed something that was broken.
Like you, however, CM seems to have reverted back to being unable to communicate or download directly from the site - interestingly, as was always the case, thumbnails and descriptions download okay.
Sigh.