.net - VB Cross-thread Shared (static) Member Access?

I'm a newbie to threading, trying to learn it as I go. don't make any assumptions and try to explain threading concepts and rules that might seem obvious. I have a Module (Static class) as follows:

Module Main
Private ReadOnly _dbConn As SqlClient.SqlConnection
Public ReadOnly Property DBConn() As SqlClient.SqlConnection
Get
Debug.Print("Accessing DBConn")

[Code]...

All throughout the application, when i access DBConn on the same thread, it works as expected. howeve, later on I created a background worker that tries to access DBConn and nothing happens, the thread just hanges (the Background worker). I dont get the printout and the application doesnt continue. the background worker thread doesnt continue past that point, and so the thread never exits. I dont get any exceptions, and i Cant debug in Visual Studio (visual studio hangs).I guess its a 2 part question: why cant i access DBConn from the other thread, and why does it hang without giving me a threadAccess exception? also, why does visual studio hang (I'm assuming it hanges because the thread is hanging)?

Please Note: I am not asking about practice. I know I shouldnt be sharing the same connection, rather returning a new connection. in this particular application it is safe since (although i execute it on a background thread) as per the flow of the application, the connection can only be accessed one at a time. I just want to know why it hangs accross the thread.