sshguard was tking several minutes to start up, and on running in debug mode, I noticed a slow processing of reverse lookups as "iptables -L" was run.
If the iptables initialization command is changed to "iptables -n -L sshguard", there are two benefits. Initialization is a snap, and there is a check for the necessary "sshguard" chain in the iptables ruleset. That second benefit might help users who think they have sshguard setup (it starts okay), only to run into an error when sshguard detects an action-worthy incident.
Fixed in e18e89b, thanks!