Backup question for KH

The VZ/PC/Maintenance screen is saying that I've reached the max number of allowed backups:

[Broken External Image]: You have reached maximum allowed number of backups.To make new backup You should remove older one.

How many backups is my account allowed and do I have to manage (delete) old backups manually?

This warning was on the page the other day when there was 1 fewer backups, yet it still created another incremental backup yesterday morning.