NV+ won't write

I've mapped the Hostname in Windows via SMB. Same as my other NAS, which works OK. I can try mapping via IP, but the truth is that I can see the shares just fine and can read from them, just not write to them in any sustained fashion.

I've ruled out there being a volume/share issue as I've managed to copy via a backup from the USB port.

I've ruled out there being a permissions problem as I am able to write individual files (at about 3-400 kb/s across a wireless connection).

I've not been able to rule out a Network problem as it only happens when writing across the network using an SMB mapping.

Also, it only happens when trying to 'bulk' write using a synchronization or copying tool, not individual files - however I'm trying to get a baseline copy of my other NAS on there as a backup.

The errors are always "network resource unavailable" or similar. It might be related to the speed/number of files being copied, which seems to take it off the network, or stop writing.

I've replaced the high ATA error rate drive as requested, but that has not solved the problem.

Thanks.