Hi Alberto,
I fired up example 3, from NetTalk 5 here and gave it a try.
I logged in with demo, Demo, and the remember me turned on.
Any request after that then includes the following in the header (you can see this in the log)
Cookie: SESSIONID=828890677; LOC__LOGIN=demo; LOC__PASSWORD=demo
this is expected (and part of what "remember me" does).
Then I logout (which brings me back to the login screen) - I log in as Demo, demo, but this time I leave the "remember me" off.
After that,
Cookie: SESSIONID=828890677
So, it looks to me like the DeleteCookie thing seems to be working ok.
did I go wrong in the process somewhere?
cheers
Bruce