i noticed a problem in 1.5.1.0, that the lsf output would get confused about a directory entry
that a file of zero bytes would appear in lsf file output but was a folder.
that was/is with s3 backends, not sure that applies to gdrive.
also not sure this is your problem.
in this post, i demonsrated the problem and how to test for it.
ncw create a beta version that fixed the issue.
perhaps the beta was not merged into the latest beta.