Filegroup backups can only be performed on databases configured to support Log backups

Hello,

I keep receiving the following error "Final error: 0xe0009417 - Filegroup backups can only be performed on databases configured to support Log backups." This has occured because I tried to backup the transaction logs (as it kept complaining that the log was growing), when a few of the database had a recovery mode of simple. I have cancelled the transaction log backups but the full database backup keeps throwing that same error.

I have already tried everything in the following article: http://www.symantec.com/business/support/index?page=content&id=TECH45850. 

Please help, no backups are being created!