Yes, unfortunately the Version 8.4 (5) is affected by this bug and many others.
The bug you mentioned was solved in version 8.4 (7)
http://www.cisco.com/c/en/us/td/docs/security/asa/asa84/release/notes/asarn84.html#pgfId-581504
I would recommend you do an upgrade. But note that Cisco has announced its EOS for version 8.4
http://www.cisco.com/c/en/us/products/collateral/security/asa-5500-series-next-generation-firewalls/eos-eol-notice-c51-732687.html
If you ASA has requirement to support version 9.2.2 (4) go ahead because is a stable release and highly recommended by Cisco.
