I'm having exactly the same problem.
I'm running Amavis-new 2.6.6. so I uncommented the same lines, with the same result.
You asked the OP to log the queries, but that is rather pointless, because the error is that binding the parameter fails, so it's the construction of the query in the DB layer that fails, it isn't even passed on for execution.
To be sure, I did a tcpdump + pt_query_digest to look at the queries run (our setup uses a central DB server, so query logging there is not an option).
How to fix this, I don't currently have any anti-spam measures active on my domains, which is quite an issue for some as we receive hunderds of spam mails a day for those domains...