PublishWorkflow error when workflow contains custom code activity

I've failed to get a custom code activity working within Workflow Manager 1.0 even though I believe I've performed all of the guidance steps provided.

As other posts, I get the usual 'cannot create unknown type' error:

client.PublishWorkflow( workflowName, @"..\..\TestWorkflow.xaml" );
->
Cannot create unknown type '{wf://workflow.windows.net/$Current/$Activities}SendMailActivity'.

The activity is implemented as:

namespace SharedActivities
{
	public sealed class SendMailActivity : CodeActivity
	{
...

I've created an AllowedTypes.xml file containing the following:

<?xml version="1.0" encoding="utf-8" ?><AllowedTypes><Assembly Name="SharedActivities"><Namespace Name="SharedActivities"><Type>SendMailActivity</Type></Namespace></Assembly></AllowedTypes>

The SharedActivities assembly has the following Post Build event command line

net stop "Workflow Manager Backend"
%systemroot%\system32\inetsrv\appcmd stop apppool /apppool.name:"WorkflowMgmtPool"

xcopy /y "$(TargetPath)" "C:\Program Files\Workflow Manager\1.0\Workflow\WFWebRoot\bin"
xcopy /y "$(TargetPath)" "C:\Program Files\Workflow Manager\1.0\Workflow\Artifacts"

copy /y $(ProjectDir)AllowedTypes.xml "C:\Program Files\Workflow Manager\1.0\Workflow\WFWebRoot\bin"
copy /y $(ProjectDir)AllowedTypes.xml "C:\Program Files\Workflow Manager\1.0\Workflow\Artifacts"

%systemroot%\system32\inetsrv\appcmd start apppool /apppool.name:"WorkflowMgmtPool"
net start "Workflow Manager Backend"
Execution output : 
1>------ Rebuild All started: Project: SharedActivities, Configuration: Debug Any CPU ------
1>  SharedActivities -> D:\Dev\Prototypes\WorkflowTest\SharedActivities\bin\Debug\SharedActivities.dll
1>  The Workflow Manager Backend service is stopping.......
1>  The Workflow Manager Backend service was stopped successfully.
1>  
1>  "WorkflowMgmtPool" successfully stopped
1>  D:\Dev\Prototypes\WorkflowTest\SharedActivities\bin\Debug\SharedActivities.dll
1>  1 File(s) copied
1>  D:\Dev\Prototypes\WorkflowTest\SharedActivities\bin\Debug\SharedActivities.dll
1>  1 File(s) copied
1>          1 file(s) copied.
1>          1 file(s) copied.
1>  "WorkflowMgmtPool" successfully started.
1>  The Workflow Manager Backend service is starting.
1>  The Workflow Manager Backend service was started successfully.
1>  
========== Rebuild All: 1 succeeded, 0 failed, 0 skipped ==========

The assembly containing the custom activity is loaded into the Workflow host process.

I've configured my machine (development) to allow unsafe types.

I've also uploaded my project so you can verify the implementation.

Thanks in advance, Adam