I think I found out the issue, apparently if both users are working on the same application, and the session variable is being saved to a public object. then on the page load of the application the object is saved to a
static variable. if I remove the static property from the variable I know longer experience the issue. I've read somewhere that static variable shares with all isntances, can anyone confirm
http://forums.asp.net/t/1694354.aspx/1
Thanks for your feedback