Before creating Software Creation packages in SCCM, you need to set up permission on source files. If the permissions are not setup correctly you see this error in “SMS_DISTRIBUTION_MANAGER”
error 2306:The source directory "\\<server>\<share>" for package "xxx00000" does not exist. The operating system reported error 5: Access is denied.
These two articles will give you more information:
http://chadstech.net/wiki/index.php?title=File_Share_for_package_source_files
http://www.windows-noob.com/forums/index.php?/topic/1090-share-and-ntfs-permissions/