An additional condition should be checked to work around the bug in servers 5.0.13 and grant that only files greater than one-chunk use the chunked interface. This line was removed from line 271 of FileUploader:

  && (new File(files[i].getStoragePath())).length() > ChunkedUploadFileOperation.CHUNK_SIZE)  

Something similar should go here with the if (mChunked && ...) condition