Still broken on 1.2.4 the last release of 1.2 unfortunately. This is the fix I used:
Change line 239 of lib/Doctrine/DataDict/Mysql.php from:
return 'DOUBLE('.$length.', '.$scale.')';
This gets rid of scale completely but I think its better than all doubles that don't have a defined scale limited to decimal places, which is just awful for anyone using the Geographical behaviour.