2.9.1 doesn't allow me to switch from visual to html post editing. I've tried disabling all plugins, and clearing the brower cache, and it still doesn't work. Other blogs I haven't upgraded from 2.8.5 work perfectly.
So I downgraded the problem Blog to 2.8.5 (replacing everything but config.php and Content folder with 2.8.5 files), and it insisted on "upgrading the database" or something like that, which reinstalls the problem!!!!
So, how to downgrade the database so it works the same as my other blogs which haven't been upgraded from 2.8.5 at all? I've got WP-DBmanager installed and tried optimising and repairing, but that doesn't help.
Chris