DataSource Controls :: Using "using" For Connection Management And Preventing Timeouts?

I had been using the "regular" System.Data syntax to create connections on web forms, like:

dim conn As New SqlConnection(ConfigurationManager.ConnectionStrings("myconnStr").ConnectionString)

dim myCommand as SqlCommand

myCommand = new SqlCommand("my sql statement", conn)

myCommand.Connection.Open()

myCommand.ExecuteNonQuery()

myCommand.Connection.Close()

I say "regular" because most examples I've seen use this syntax, but more recently I've started using:

Using conn As New SqlConnection(ConfigurationManager.ConnectionStrings("myconnStr").ConnectionString)

dim myCommand as SqlCommand

myCommand = new SqlCommand("my sql statement", conn)

myCommand.Connection.Open()

myCommand.ExecuteNonQuery()

myCommand.Connection.Close()

End Using

...because recently I've seen some examples using this syntax.Even more recently, I've discovered that I'm getting some connection timeouts on a busy website I created a couple years ago. After googling the error, I found a few threads stating that the second example above will provide immediate automatic cleanup of connections, and in looking over the website, I'm using the first syntax exclusively.

My question is, am I creating the problem by not fully tearing down the connections in my code above (merely closing them, but not actually destroying them)? Do I need to do something like "set conn = nothing" like I used to do in VBScript?

And if so, will using the second syntax take care of this problem?