Automatic cleanup rules not working correctly...

I appreciate any help as I cannot figure out what is wrong. I have attached and included two screen capture images which will hopefully help me explain my issue.

As you can see my configuration for this backup task is set to create a new backup every 6 incremental versions. The old version cleanup rule is set to delete version chains older than 90 days.

The second image shows the actual file backups on the backup hard drive. The most recent date of the backup version b1_s1_v1 - b1_s7_v1 is 12/4/2012. Today is 3/17/2013, making it greater than 90 days. Why is this backup version chain still there? Shouldn't it be deleted automatically?

Thanks for any help you can provide.