How does the COM+ transaction timeout work?

I do not understand, how the transaction timeout works in COM+. I have the class ClassComPlus which inherits from ServicedComponent, has transaction timeout attribute set to 1 second, and has a method SubSleep, that sleeps 3 seconds. I expect, the client which calls the method SubSleep to get an exception, because the transaction timeout has elapsed, but I do not get such an exception, the method completes without an exception.

Here is the code in VB.NET. I am sorry it is not in VB6, but unfortunately they could not help me in the VB.NET forums, because they say that COM+ is outdated, and that it was used primarily by VB6 developers.

1. Project Test1BO.vbproj as Class Library signed with a strong key, having the two files:

1.1 AssemblyInfo.vb:

Imports System.EnterpriseServices
Imports System.Reflection
Imports System.Runtime.InteropServices
<Assembly: ApplicationActivation(ActivationOption.Server)>
<Assembly: ApplicationAccessControl(CType(AccessChecksLevelOption.Application, Boolean))>
<Assembly: Guid("799facfd-af56-4496-bc18-618e2522e5f7")>
<Assembly: AssemblyVersion("1.0.0.0")>
<Assembly: AssemblyFileVersion("1.0.0.0")>

1.2 ClassComPlus.vb

Imports System.EnterpriseServices

<Transaction(TransactionOption.Required, isolation:=TransactionIsolationLevel.ReadCommitted, timeout:=1), _
EventTrackingEnabled(True), _
JustInTimeActivation(True)> _
Public Class ClassComPlus
Inherits ServicedComponent

Public Sub SubSleep()
Try
Threading.Thread.Sleep(3000)
ContextUtil.SetComplete()
Catch
ContextUtil.SetAbort()
Throw
End Try
End Sub
End Class

Test1BO must be registered in COM+ for example with the following RegisterComPlus.bat file in the folder where the dll is created:

set regsvcs=C:\Windows\Microsoft.NET\Framework\v4.0.30319\regsvcs
set topdir=%~dp0
set dllname=Test1BO
%regsvcs% /u "%topdir%\%dllname%.dll"
%regsvcs% "%topdir%\%dllname%.dll"
pause

2. Project Test1CA.vbproj as Console Application with reference to Test1BO.dll has just Module1.vb:

Module Module1
Sub Main()
Dim obj = New Test1BO.ClassComPlus
Try
obj.SubSleep()
Console.WriteLine("SubSleep finished normally (unexpected)")
Catch ex As Exception
Console.WriteLine("SubSleep threw exception (expected)")
Console.WriteLine(ex.ToString)
Finally
obj.Dispose()
End Try
Console.ReadKey()
End Sub
End Module

I would expect, that because the transaction timeout is 1 second, but the sleep time is 3 seconds, that the statement obj.SubSleep would throw an exception. Instead, obj.SubSleep finishes normally.

1. What am I doing wrong?
2. Did I wrongly understood the transaction timeout?