Application incompatibility in SMB 2.0(Vista)

I notcied application incompatibility in SMB 2.0(Vista).

When a program creates a network share file with FILE_FLAG_NO_BUFFERING
and writes data less than 512 bytes
WriteFile() ends up with 87(ERROR_INVALID_PARAMETER,0xc000000d).
This symptom occurrs only in Vista-Vista connection. i.e. SMB 2.0

It’s true that we get sector boundary restriction
when we open a local disk file with FILE_FLAG_NO_BUFFERING.
But AFAIK we don’t have any boundary restriction
to read/write a network share file.

My questions are:
(1) Is this a specification change or bug?
If this is a specification change
this is one of application incompatibility.
If specification change.
(2) Do you know any statement about it?
(3) Is there any programable way to distiguish SMB 1.0 and 2.0 ?
(4) Is there any way to force to use SMB 1.0 ?

Thanks for any information.

Ichiro Akimoto