13.33 is the Stable Release Candidate so it isn't full release yet. But I haven't tested so perhaps some others can chime in. I know some folks going to later firmwares were having appliance reboot issues.
Adam R MS | CISSP, CISM, VCP, MCITP, CCNP, ITILv3, CMNO If this was helpful click the Kudo button below If my reply solved your issue, please mark it as a solution.
Strange, but I wouldn't worry to much about it. The stable release candidate 13.33 is basically a stable release so you should be fine. If you click the firmware number in the dashboard it'll show the release notes. This article spells out some of it.