Rescue and Recovery backup never completes

I've never been able to get Rescue and Recovery to complete a backup to my NAS in the year I've owned my x201. It starts fine and will usually go for an hour or so, but then I either start getting warnings about files in use, or it ends up shutting down my wireless connection completely (requiring a full reboot of the router/modem and PC to fix). Any suggestions on how I can get this to work? I found a help page that mentioned difficulties when backing up to some network storage devices that run Linux (which mine does) and it says to set Rescue and Recovery to backup to both the local drive and the network storage, but I haven't been able to figure out how to do this in the settings, it seems to be one or the other.

 

Update: After I posted I tried again, but plugged into Ethernet. This time I finally got the backup to complete. It took about 12 hours, and I manually had to tell it to skip numerous files that it said were either corrupt or in use (mostly seemed to be files in Z:/preboot if that matters). So I'm glad to have it finally work, but I'd like to have it be more of a background process without me having to intervene multiple times over a 12 hour period. Is there a way to tell it to automatically skip corrupt files?