Mr. Orange-
I had no trouble getting your code up and running in 15 minutes - happily logging, saving, and reading the input to analog1.
However, after hitting the arduino reset button, I found that the read function returns junk(from the SD card).
Shouldn't the SD card retain data after a power cycle? or, is it a function of the code that you so nicely supplied to get me started - and I just don't understand it, yet?