Chained SQL Server setup doesn't work with SQL2014 express

I had an MSI setup that installed, through Custom Action, SQL Server 2008 express based on some conditions.
Everything used to work just fine until I changed the SQL Server to 2014 express.

It seems that the 2014 setup procedure opens SCM and waits for msiexec to stop before executing the installation (maybe it's checking for another installation running and waits for it to finish).

In this way the SQL Setup waits forever (because it's run inside the same installation it's waiting to finish).
Is there a way to tell the Sql Setup to not wait? Something like a /chain switch?

[...]
(01) 2014-04-24 20:28:09 Slp: Checkpoint: INSTALL:SHUTDOWNNONINSTANCE:SQL_BROWSER_REDIST
(01) 2014-04-24 20:28:09 Slp: Completed Action: SqlBrowserConfigAction_install_ShutdownNonInstance_Cpu32, returned True
(01) 2014-04-24 20:28:09 Slp: Completed Action: PreMsiTimingConfigAction, returned True
(01) 2014-04-24 20:28:09 Slp: ----------------------------------------------------------------------
(01) 2014-04-24 20:28:09 Slp: Running Action: CachePatchPackage
(01) 2014-04-24 20:28:09 Slp: Completed Action: CachePatchPackage, returned True
(01) 2014-04-24 20:28:09 Slp: ----------------------------------------------------------------------
(01) 2014-04-24 20:28:09 Slp: Running Action: InitializeMsiAction
(01) 2014-04-24 20:28:09 Slp: Sco: Attempting to create base registry key HKEY_LOCAL_MACHINE, machine 
(01) 2014-04-24 20:28:09 Slp: Sco: Attempting to open registry subkey SOFTWARE\Microsoft\NET Framework Setup\NDP\v2.0.50727
(01) 2014-04-24 20:28:09 Slp: Attempting to pause the 32 bit ngen queue for x86
(01) 2014-04-24 20:28:09 Slp: ngen command to be used from .Net Framework Directory: C:\Windows\Microsoft.Net\Framework\v2.0.50727
(01) 2014-04-24 20:28:09 Slp: Running: C:\Windows\Microsoft.Net\Framework\v2.0.50727\ngen.exe queue pause
(08) 2014-04-24 20:28:10 Slp: Microsoft (R) CLR Native Image Generator - Version 2.0.50727.5420
(08) 2014-04-24 20:28:10 Slp: Copyright (c) Microsoft Corporation.  All rights reserved.
(08) 2014-04-24 20:28:10 Slp: 
(08) 2014-04-24 20:28:10 Slp: The .NET Runtime Optimization Service is started and paused.
(01) 2014-04-24 20:28:10 Slp: Process returned 0
(01) 2014-04-24 20:28:10 Slp: Completed Action: InitializeMsiAction, returned True
(01) 2014-04-24 20:28:10 Slp: ----------------------------------------------------------------------
(01) 2014-04-24 20:28:10 Slp: Running Action: MsiTimingAction
(01) 2014-04-24 20:28:11 Slp: ----------------------------------------------------------------------
(01) 2014-04-24 20:28:11 Slp: Running Action: Install_WatsonX86_Cpu32_Action
(01) 2014-04-24 20:28:11 Slp: SetFeaturePropsModifyInstallAction for WatsonX86_Cpu32 
(01) 2014-04-24 20:28:11 Slp: Sco: File 'C:\temp\Setup\ISSetupPrerequisites\Microsoft SQL Server 2014 Express ITA\redist\watson\x86\dw20shared.msi' does not exist
(01) 2014-04-24 20:28:11 Slp: Sco: Attempting to create base registry key HKEY_LOCAL_MACHINE, machine 
(01) 2014-04-24 20:28:11 Slp: Sco: Attempting to open registry subkey 
(01) 2014-04-24 20:28:11 Slp: Sco: Attempting to open registry subkey SOFTWARE\Microsoft\VisualStudio\10.0
(01) 2014-04-24 20:28:11 Slp: Sco: Attempting to open registry subkey SOFTWARE\Microsoft\VisualStudio\11.0
(01) 2014-04-24 20:28:11 Slp: Sco: File 'C:\temp\Setup\ISSetupPrerequisites\Microsoft SQL Server 2014 Express ITA\redist\watson\x86\dw20shared.msi' does not exist
(01) 2014-04-24 20:28:11 Slp: Sco: File 'C:\temp\Setup\ISSetupPrerequisites\Microsoft SQL Server 2014 Express ITA\redist\watson\x86\dw20shared.msi' does not exist
(01) 2014-04-24 20:28:11 Slp: Checkpoint: PREINSTALL_WATSONX86_CPU32_ACTION
(01) 2014-04-24 20:28:11 Slp: Sco: Waiting for service 'msiserver' to accept the stop request.
(01) 2014-04-24 20:28:11 Slp: Sco: Attempting to open SC Manager
(01) 2014-04-24 20:28:11 Slp: Sco: Attempting to open service handle for service msiserver
(01) 2014-04-24 20:28:11 Slp: Invoking QueryServiceStatus Win32 API
(01) 2014-04-24 20:28:11 Slp: Sco: Attempting to close service handle for service msiserver
(01) 2014-04-24 20:28:11 Slp: Sco: Attempting to close SC Manager
(01) 2014-04-24 20:28:16 Slp: Sco: Attempting to open SC Manager
(01) 2014-04-24 20:28:16 Slp: Sco: Attempting to open service handle for service msiserver
(01) 2014-04-24 20:28:16 Slp: Invoking QueryServiceStatus Win32 API
[...] and loops like that...