Does the BES admin tool, computer cleanup, have a App lock?

Does the BES admin tool, computer cleanup, have a App lock? Something to prevent two instances from running at the same time?

We have a schedule cleanup that runs every 4 hours. Yesterday when it ran, there was another, manually created cleanup occurring at almost exactly the same time. I believe this caused issues because computers that had expired x days ago was much smaller than we normally set.

The BES admin logs see both instances running and even show a SQL deadlock error messages.

Short of us having to look to see if an instance is already running, I am wondering if there was a built in process that just happened to fail.

Before you ask, I have been asked many times before why we run the scheduled cleanup every 4 hours. We do this for two reasons, we refresh our reporting data visible to customers every 4 hours and we have dozens of customers with Citrix PVS servers. These server are spun up on demand and powered off when the last person logs off. Each time it boots, it gets a new computer ID. This causes many duplicates to appear in the console and customers do not like to see duplicates.