SSIS variable locking may not be doing what you think it's doing

"Read-only and read-write locking only differ in how the lock on the variable is done not in what you can do with the variable when it's locked. For example a variable can only be locked for read-only access by multiple tasks successfully but only one task can lock it for read-write (and no read-only access is permited (sic) during the time) at one point in time."

http://forums.microsoft.com/MSDN/ShowPost.aspx?PostID=3909052&SiteID=1

The behaviour wasn't what I was expecting and I need to digest the official MS response. My initial thought is that the naming is "wrong" for what it does.  

And since I started to blog about this, that definitive answer has been smacked down.  I've started working on an example that I hope will show what putting a variable in readonly vs readwrite does but so far, I can't make SSIS show a difference.  Win XP, SP2, 9.00.3042.00

Rough attempt on my skydrive