fat16lib:
SD.h still uses the 2009 version of SdFat in 1.6.7, very little has changed.Running the latest version of SdFat on 1.0.6 may be a problem, I don't test on very old versions of the IDE.
If you don't need new features like long file names you could just use the old SD.h.
There are many unfixed bugs but they seem to only bite a few users.
Has the how do the speeds of writing to files differ between the libraries?
Thanks again.