RE: word tmp file encrypt problem?

I come back to this project recently.
I solved this proble with two ways.
The first is when winword rename .tmp file to .doc file, I create the .doc file,
add extra data to it’s head, then read from .tmp file , encrypt the data and
write it to .doc file;
The second is when winword create the .tmp file, I encrypt the data write to it, when renaming I create the .doc file, add extra data to .doc , then read
data from .tmp file, decrypt it and encrypt it and write it to .doc file.
Thesetwo ways both work correctly.

But I am wondering why I would fail if I add extra data to .tmp file when it’s created!
I watch the output from filemon , the result of FastIoQueryStandardInfor is not
same as FastIoWrite result. How can this occur? May someone point out the cause!