How to disable rewrite_header Subject for one user?

[Jason von Nieda]

Hi all. I'm using SA with rewrite_header Subject globally but I need to 
disable it for one user. I used to use rewrite_subject 1 globally and 
rewrite_subject 0 in user_prefs for this user but with 3.0 these are 
deprecated and removed. Can someone give me a hint of how to do this now?
I've tried putting just "rewrite_header Subject" (without quotes) in 
user_prefs but that still adds one space to the Subject header.
Thanks for any help!

Jason von Nieda