VB.NET: ExecuteReader(CommandBehavior.CloseConnection) hangs after running SQL Query

I am trying to execute a SELECT SQL statement which returns a value to me. The following is my code to Get the value from the SQL select statement.

Private objSQLHelper As SQLHelper

Private Const SQL_Error_Query = "SELECT field1 FROM TESTTBL WHERE field1ID = @field1ID;"

Public Function GetField1(ByVal field1ID As Integer) As Boolean
    Dim sdr As SqlClient.SqlDataReader = Nothing
    Dim sqlParams As New ArrayList
    Dim resultBool As Boolean

    sqlParams.Add(New SqlClient.SqlParameter("field1ID", SqlDbType.Int))
    sqlParams(0).value = field1ID

    sdr = objSQLHelper.sdrExecuteReader(sqlConnectionString, CommandType.Text, SQL_Error_Query, sqlParams)

    While sdr.Read()
        resultBool = CBool(sdr("field1"))
    End While

    sqlParams.Clear()

    Return resultBool
End Function

Inside the sdrExecuteReader function, the code always gets stuck at the line with CommandBehavior.CloseConnection. For the above GetField1 function, this simple SELECT query statement caused this. However, other SELECT queries that belong to other files is working and they also call the same sdrExecuteReader function. Thus, I am unsure why for the GetField1 function the code hangs at the line with CommandBehavior.CloseConnection. Below is how the sdrExecuteReader function looks like:

Public Function sdrExecuteReader(ByVal sqlConnectionString As String, ByVal commandType As CommandType, ByVal commandString As String, ByVal sqlParams As ArrayList) As SqlClient.SqlDataReader
    Dim sqlCommand As New SqlClient.SqlCommand
    Dim sqlConnection As SqlClient.SqlConnection = Nothing

    Try
        openingConnection = New SqlClient.SqlConnection(sqlConnectionString)
        PrepareCommand(sqlCommand, sqlConnection, Nothing, commandType, commandString, sqlParams)

        ' Code always gets stuck or hangs at this line
        sdrExecuteReader = sqlCommand.ExecuteReader(CommandBehavior.CloseConnection)
    End Try
End Function

Questions:

1. Does anyone know why this happens? I do not wish to change my sdrExecuteReader function as much as possible because many functions rely on it.
2. Is there anything I can write in my GetField1 function to debug or anything I can include to fix the code inside that function?
3. If qns 1 and 2 cannot be answered, what are the reasons that this is happening?

Note: When I change SQL_Error_Query to "SELECT field1 = 1" (basically hard coded), it works. Possibly the sql connection is not working? but other select queries are working though...

you can enclose lines with try/catch and use debugger. have a look to PrepareCommand : problem can be in SQL connexion, in Query or in parameter.
as I don't know SQLHelper wrapper, I test your query by using standard SQLclient. this is the code (tested OK). maybe help you to investigate.

Imports System.Data.SqlClient

    Public ConnSQL As New SqlConnection("your connexion string;")
    Const SQL_Error_Query = "SELECT field1 FROM TESTTBL WHERE field1ID = @field1ID;"

    Public Function GetField1(ByVal field1ID As Integer) As Boolean

        Dim resultBool As Boolean

        Dim sqlParams As New SqlParameter
        sqlParams.ParameterName = "field1ID"
        sqlParams.SqlDbType = SqlDbType.Int
        sqlParams.Value = field1ID

        ConnSQL.Open()
        Try
            Dim cmdSQL As New SqlCommand(SQL_Error_Query, ConnSQL)
            cmdSQL.Parameters.Add(sqlParams)
            Dim sdr As SqlClient.SqlDataReader = cmdSQL.ExecuteReader()
            While sdr.Read()
                resultBool = CBool(sdr(0))
            End While
        Catch ex As Exception
        End Try

        ConnSQL.Close()

        Return resultBool
    End Function

In sdrExecuteReader instead of returning the sqldatareader directly to the caller, create a dataset that holds the data and return another datareader that references this dataset. Try this and see if it resolves your issue.