[?!] Rsync problems with "--delete" option

I am trying to run rsync with the --delete option and am running into problems.

My command line is:

rsync --archive --stats --delete-during /mnt/cache/unRAID_Apps/YAMJ/YAMJ_FLASH_Jukebox_Local/ /mnt/cache/unRAID_Apps/PCH_LivingRoom/

The destination folder: /mnt/cache/unRAID_Apps/PCH_LivingRoom/ is a mount point to a network location - a shared folder on my Popcornhour C-200.

The copy part runs OK (no problems).

The problems start with the --delete option doing it's work:

When there are files to delete in the destination folder each file being deleted creates the following in the syslog:

Mar 13 23:12:51 Tower kernel: ------------[ cut here ]------------
Mar 13 23:12:51 Tower kernel: WARNING: at fs/inode.c:280 drop_nlink+0x1b/0x33()
Mar 13 23:12:51 Tower kernel: Hardware name: X7SPA-HF
Mar 13 23:12:51 Tower kernel: Modules linked in: vboxnetflt(O) vboxnetadp(O) vboxdrv(O) md_mod xor tun sg coretemp hwmon i2c_i801 i2c_core ahci libahci e1000e
Mar 13 23:12:51 Tower kernel: Pid: 15120, comm: rsync Tainted: G W O 3.4.26-unRAID #2
Mar 13 23:12:51 Tower kernel: Call Trace:
Mar 13 23:12:51 Tower kernel: [] warn_slowpath_common+0x77/0x8c
Mar 13 23:12:51 Tower kernel: [] ? drop_nlink+0x1b/0x33
Mar 13 23:12:51 Tower kernel: [] ? drop_nlink+0x1b/0x33
Mar 13 23:12:51 Tower kernel: [] warn_slowpath_null+0x1d/0x1f
Mar 13 23:12:51 Tower kernel: [] drop_nlink+0x1b/0x33
Mar 13 23:12:51 Tower kernel: [] cifs_unlink+0x1bd/0x2f8
Mar 13 23:12:51 Tower kernel: [] vfs_unlink+0x4c/0xb1
Mar 13 23:12:51 Tower kernel: [] ? __lookup_hash+0x1a/0x5a
Mar 13 23:12:51 Tower kernel: [] do_unlinkat+0x95/0x109
Mar 13 23:12:51 Tower kernel: [] ? fput+0x13/0x15
Mar 13 23:12:51 Tower kernel: [] ? filp_close+0x5b/0x63
Mar 13 23:12:51 Tower kernel: [] sys_unlink+0x10/0x12
Mar 13 23:12:51 Tower kernel: [] syscall_call+0x7/0xb
Mar 13 23:12:51 Tower kernel: ---[ end trace 6b67bfd5da013859 ]---

I have tried different "--delete" options all with the same result (above): "--delete" / "--delete-during" / "--delete-delay" / etc...

What does it mean and how can I fix it?

Edit:

When I try it on a local destination folder there is no problem ... ?!

Edit:

I have found this:

https://bugzilla.redhat.com/show_bug.cgi?id=816472

Can this be an issue in unRAID kernel as well?