Public Folder Backup

In the organization where I work we are using MS Exchange 5.5 Public Folders with Outlook clients, and it is working ok. Users write – post – tasks in a public folder with no problem.
But I heard someone saying the Exchange Backup is not guaranteedmeaning if there’s a problem with the server the public forders may be lost, even or because of replication with other Exchange servers in our network. Is this true? And if it’s true, is there a better way of backingup the public folders?
Thanks
Manuel Figueiredo