Sometimes I just need to jot myself some notes so I don't forget them. In this case, this page on MacWindows.com has helped me greatly in the past (and will again in the very near future), and it may help others who find odd SMB access errors, slowness, or other problems (especially on older Mac OSs).
In this newer case, I think the problem is crappy firmware for the WD Sharespace... Need to convince the owner that a Synology or QNap or Drobo would be a far better thing to trust their business data to. At least they have backups...