A few comments:

• XML does not have the concept of lines, it has the concept of element, so try not to use a line metaphor when you think of XML data, a tree works better.
• then I will have to concur with arturo (and not only with his usage of XML::Twig ;--) : if you want to use XML::Simple, load the config data and dump it using Data::Dumper or YAML, it will make it much easier for you to figure out what's going on (alternatively you can use the debugger by running perl -d and use x $XMLConfig),
• finally, is there any specific reason why you want to use XML here? I find YAML to be easier to read and to edit than XML. After fixing the typo in your XML, perl -MYAML -MXML::Simple -e 'print Dump XMLin "config.xml"' will give you this:
  

  --- #YAML:1.0
  item:
    SomeDatabase:
      dbName: SomeDatabase
      dbPass: password
      dbuser: SomeUser
      type: MySQLDB
    SomeFilesFiles:
      path: '/home/globalherald'
      type: Filesystem
  logprefix: '/var/log/sbackup'
  storage: '/home/backups'
  [download]