[FileAPI] Result of calling MultipleReads on FileReader

As we continue to experiment with the File API, I'm trying to understand the
rationale for the Multiple Reads section:
http://dev.w3.org/2006/webapi/FileAPI/#MultipleReads

The spec says:

   If multiple read methods are called on the same FileReader object, user
   agents MUST only process the last call to a read method, which is the
   call that occurs last in a script block that has the "already started"
   flag set [HTML5].

I'm trying to understand the rationale for respecting the LAST call - is it
common for people to call read lots of times and want the last one to be
respected. Since the read happens asynchronously, we'd rather kick off the
read operation as soon as the first read is called and give an error to
subsequent read calls. I'm not sure what the use case is for wanting the last
one (you can always call abort() and start again).

Is there a reason for the current spec text?

Thanks,

Adrian.

-- 
Adrian Bateman
Program Manager - Internet Explorer - Microsoft Corporation
Phone: +1 (425) 538 5111
Email: mailto:adrianba@microsoft.com