Backups not crossing mount point

I have four file servers in a single policy with the bulk of their data sitting on mount points. I have the Cross Mount Points checked off (always have), but we just found out through a restore attempt that the backups have not been traversing the mount point since August. I have created a new test policy and reran the backup on just one of the four servers with the same results. Any thoughts?

Running NBU 7.6.0.1 on Windows 2008 Master.