alt text, description, and title do not get written to database

Content Construction Kit (CCK) 6.x-2.1
ImageField 6.x-3.0-alpha3
File system Writable (public download method)
Enable custom alternate text (checked)
Enable custom title text (checked)
Description field: Enabled

Expected result: data should be serialized and written to data field
In fact, they do not:

*************************** 1. row ***************************
vid: 33264
nid: 33264
...
other cck field data
...
field_image_fid: 12047
field_image_list: 1
field_image_data: a:5:{s:3:"fid";s:5:"12047";s:5:"width";i:447;s:6:"height";i:600;s:8:"duration";N;s:11:"description";s:0:"";}