Jeffrey Williams (5/22/2008)
The standard maintenance cleanup task will not remove files that are not native backup files. Since you are using a 3rd party backup utility (SQL Litespeed?), you need to use their tool to cleanup backup files, or roll your own utility.
Since you are providing the file extension you want deleted, I don't understand why the cleanup task would not remove files outside of the native backup. My understanding is that it compares the date/time on the file plus the extension to determine what to delete, not the contents.