Perplexing sponataneous drive renaming

[footfootfoot]

I recently installed a pair of Western Digital 750GB external drives to store my photos and to back up. The first drive installed was called G (not his real name) and the second drive was called M (also not his real name) The other day G spontaneously renamed itself K, thus obliterating several thousand pictures from Picasa. I named it G again, waited for Picasa to relocate all the pictures and it was fine. Until this morning when I opened Picasa, went to click on an image and all of a sudden all the thumbnails disappeared and it was because G drive was now K once again.

WTF?

I just changed it back again, making sure that no other drive (USB port) was assigned G. Picasa is doing its thing, we'll see how long this lasts