another thought. from the default.ini:
Code:
## (Plugin Only) - You can also populate calibre custom columns with
## the site specific metadata using custom_columns_settings (but only
## if 'Allow custom_columns_settings from personal.ini' is checked in
## the plugin GUI config.) There are three parts, the entry name,
## then the label of the calibre custom column, then (optionally) a
## 'mode'. 'r' to Replace any existing values, 'a' to Add to existing
## value (use with tag-like columns), and 'n' for setting on New books
## only. (Default is 'r'.)
do you get different results with 'a' rather than 'r'?