oh yeah........... another thing I forgot to tell you...
apart from the
forum permissions you also have to set all user groups to allow them post...
AdminCP ->
Users and Groups ->
Manage User Groups ->
Edit Group -> in
Global settings -> and fill the size for
POST: Max upload file size (in KB ) then click
Complete Edit...
It should work................if not I would actually need to see your adminCP to see if all settings are correct...