It seems that the latest commits broke the choose signals.
If there is a train waiting (for full load) on the original platform (the one targeted from the schedule) arriving trains seem not to be able to select a different platform.
Tested on r8806 and r8804 (8805 does not seem to touch relevant files)
Reverting to r8803 fixes the problem
--edit--
Corrected working and not working svn version numbers
Should be fixed in r8811
Just tested it. Seems to be fixed indeed