Fail to Copy File or Folder

Recently, I have set up a data backup task from Acronis True Image Home 2009 on a Lenovo T500 running Windows Vista Business Edition 64bit. The backup task is scheduled to backup data from the Lenovo to a Netgear ReadyNAS Pioneer Pro. I have configured the backup task to backup both tib file as well as a flat file reserve copy to the same location on the ReadyNAS. When the task runs, the tib portion of the backup completes properly, however half way through the flat file backup portion, I start getting pop-up errors reporting that files cannot be copied. Once I get this pop-up, the backup is paused until I select to ignore to the file. The files that it is having issues with seem to be .URL files (all the files in the IE Favorites folder), .eml files, some pdf files as well as a number of other files. I need to resolve this problem as not only does this issue pauses the scheduled backup (scheduled to run at 2am) but at the very least I WANT to backup the .url and all selected .pdf files. I am uncertain if this is an issue with Acronis or some security issue with Windows Vista. If you can direct me to how to resolve this issue, that would be helpful.