Sorry this slipped by me for so long. An update would be advisable, but let’s try two things. First- disable all extensions- big button on the upper-right in ‘Admin- Utilities- Extensions Manager’. Now go to add a new entry in that weblog- allow comments still unchecked by default?
If so- let’s double check the db. In ‘Admin- Utilities- SQL Manager- DB query form’ run
SELECT weblog_id, deft_comments FROM exp_weblogsWhat’s that come back with?