Win7 clobbers filenames copied to a NAS drive

My setup: Windows 7 Pro (locale: Polish) and a NAS drive (D-Link DNS-323) attached via a router. Just recently upgraded from XP to 7. The NAS drive reports an NTFS partition.

The problem I've just discovered: when copying files to the NAS drive, if a filename contains certain characters, such as curly quotes, angle quotes, bullet characters, subscript characters, em-dash etc., only the short 8.3 filename gets copied to the NAS drive. So a file named Abc „def” – ghi « jklm.htm on the Win7 system becomes Abcde~6h.HTM on the NAS drive.

(I would not sweat it if the troublesome characters just got dropped, but what happens is that meaningful filenames are replaced with gibberish as above.)

I use the NAS drive as a backup/mirror location for the local drives, so this is a big issue, since my backups are now severely clobbered. I discovered the problem while testing my backup regime, then found out the filename change occurs no matter how the files are copied - whether it's the backup application, a file manager or just Windows Explorer.

And (of course) the problem did not occur when I was running XP, and nothing on the NAS drive changed since I installed 7 a week ago. Files that were previously copied onto the NAS drive (under XP) still show up fine, which tells me that 7 is actively interfering with the copy operations.

Does anyone know why this happens or if there is a workaround? Thanks a lot in advance for any suggestions.

Updating the firmware in the NAS device and reformatting it seems to have solved the problem.

I would still love to know exactly what Win7 does with respect to the NAS drive handling, since the problem was not present under XP SP3, which I was previously using, so the OS must be affecting it in *some* way.