Found the LSRecovery tool at
http://www.yousendit.com/download/QlVnSU5KYUk4NVVLSk5Vagby googling
buffalo lsrecovery
and finding the link at the end of the post.
Used the tool to reset the pwd to the default. Then got into the Web UI to reshare my shared folder on the NAS.
In summary:
1. Electrical power turning rapidly on an off caused my Buffalo cloudstor NAS (CS-WV2.0/1D) to go into Emergency Mode. Couldn't get to Web UI and couldn't access shares. But I could still ping the NAS and see it from NAS Navigator. I could tell it was in Emergency Mode because its name now contained the added letters "EM".
2. Factory reset procedure using function key had no effect.
3. I found the firmware at
https://www.buffalotech.com/products/cloudstor-personal-cloud-storage and updated it. This got me back the NAS Web UI, but I still couldn't get in because my old password wouldn't work.
4. Found the LSRecovery tool at
http://www.yousendit.com/download/QlVnSU5KYUk4NVVLSk5Vag and used the tool to reset the pwd to the default.
5. Still could not see my share. So went to the "Folders" section in the WebUI, found my folder, double clicked it to get to the folder's Properties page, confirmed that it was set to be shared to Everyone in Windows and Mac, and clicked Apply. I was immediately able to see my shared folder and files in the subfolders in the folder. The NAS started grinding away (probably explicitly resetting all the permissions). But I'm still able to see all my folders and files.
Hope this helps somebody.