RDR change cache state async in vista

before vista(win XP,win 2000),If I issue my byte range lock in my minifilter,the RDR will change cache state sync(oplock break).
But in vista,in the same situation,the RDR will change cache state async(oplock break).

In my minifilter,my solution is issue my byte range lock to oplock break.
But because it’s async in vista,I must wait 50ms for the RDR change the cahce state.

How can I make the RDR change it’s cache state sync?
or
Can I get the notification for the RDR have changed it’s cache state?


And
why in winxp,win2000,the RDR do it sync,but in vista the RDR do it async…?

anybody know it?
maybe someone from microsoft know it?