Strange compilation error in machine.config

As my colleague Tess told a while ago, sometimes the problems seems to come in bunches; so it happened that I saw the following error message from two different customers in less than a week...

Server Error in '/' Application.

---

Configuration Error

Description: An error occurred during the processing of a configuration file required to service this request. Please review the specific error details below and modify your configuration file appropriately.
Parser Error Message: This config section already contains an identical line, which is not allowed.
Source Error:

Line 350:   extension=".js"
Line 351:      type="Microsoft.JScript.JScriptCodeProvider, 
                  Microsoft.JScript, 
                  Version=7.0.5000.0, Culture=neutral, 
                  PublicKeyToken=b03f5f7f11d50a3a" />
Line 352:   </compilers>
Line 353:
Line 354:   <assemblies>

Source File: c:\windows\microsoft.net\framework\v1.1.4322\Config\machine.config    Line: 352

Unfortunately this error message is a bit misleading, and you get this problem if you run multiple installations of a Device Update for Outlook Mobile Access (OMA), without have first uninstalled previous versions of this update.

To resolve the problem, open your machine.config file and check line #359 and #367 (please note that the line numbers may vary a bit, depending if you have installed other components which have changed your machine.config):
- line 359: assembly="System.Web.UI.MobileControls.Adapters,Version=1.0.0.0,Culture=neu­tral,PublicKeyToken=b03f5f7f11d50a3a" />
- line 367: assembly="System.Web.UI.MobileControls.Adapters,Version=1.0.0.0,Culture=neu­tral,PublicKeyToken=b03f5f7f11d50a3a" />

Both lines should be the same. Next, remove the section that belongs to line 367 like below:

<!--
BEGIN section inserted by Device Update 2 installer.
--> 

<add assembly="System.Web.UI.MobileControls.Adapters,Version=1.0.0.0,
        Culture=neutral,PublicKeyToken=b03f5f7f11d50a3a" />

<!--
END section inserted by Device Update 2 installer.
-->

Again, please note that I've neen this error with bith Device Update 2 and Device Update 4, so look carefully at your machine.config since the above may vary a bit.

I have to admit than the first time I saw this error finding the real problem took me some time (time that luckily I saved with the secont customer... :-) ), so I hope this is useful in case you see this error...

That's all folks!

Cheers
Carlo