Strange problem with extended ASCII/Unicode on network drive

Hello,

I recently purchased SyncBackPro and am running version 6.5.4.0 on Windows 7 64-bit. I'm trying to synchronize files from my NTFS-formatted local hard drive a Synology NAS with an NTFS formatted drive, but every file with extended ASCII or Unicode characters appears to be failing, despite both drives supporting Unicode. The files copy fine if I do them manually in Windows Explorer. The error log lists the two drives as follows:

Local: D:\XXX
Drive Type Fixed
Volume Name XXX
Volume Serial XXX
Max. Component Length 255
Properties Case Preserved, Case Sensitive, Unicode, ACLs, Supports Compression, Supports Disk Quotas, Supports Sparse Files, Supports Reparse Points, Supports Object Identifiers, Supports the Encrypted File System, Supports Named Streams, Supports Extended Attributes, Supports Hard Links, Supports Open by FileID, Supports Transactions, Supports USN Journal
Format NTFS
Free disk space 133520MB

Remote: \\XXX\XXX
Drive Type Remote
Volume Name XXX
Volume Serial XXX
Max. Component Length 255
Properties Case Preserved, Case Sensitive, Unicode, Supports Disk Quotas, Supports Object Identifiers, Supports Named Streams
Format NTFS
Free disk space 248510MB

But fails on any file that has characters like "é", "ô", "à" and so forth. Any ideas what might be causing this? Thanks.