Incremental Scan W/ GroupShield 6

[LungFu]

I'm trying to setup incremental on demand scan on my information stores using GroupShield 6 and not having success. The scheduled task I setup scans the entire store every time. When we were on GroupShield 5.2 the on demand scans could be setup to scan only mail received since the last scan (incremental). The GroupSield 6 Upgrade Guide indicates that you have to use resumable scanning to get incremental scanning but it doesn't give any detail on how to set it up.
I've attempted this on a test server with a small information store (300-400 mg). It appears to scan the entire store each time regardless to how I configure the resumable scan.
Does anyone know how to configure incremental on demand scans in GroupShield 6?
Thanks.