I'm having the same problem. Completely sporadic with it being worse on some hardware models. We have a very simple unattend file though so I'm curious where we would enter that wait. Here is a copy of our unattend.xml. Thanks..
<?xml version="1.0" encoding="utf-8"?>
<unattend xmlns="urn:schemas-microsoft-com:unattend">
<settings pass="specialize">
<component name="Microsoft-Windows-Shell-Setup" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<CopyProfile>true</CopyProfile>
<TaskbarLinks>
<Link0>%ALLUSERSPROFILE%\Microsoft\Windows\Start Menu\Programs\Microsoft Office\Microsoft Outlook 2010.lnk</Link0>
<Link1>%ALLUSERSPROFILE%\Microsoft\Windows\Start Menu\Programs\Microsoft Office\Microsoft Word 2010.lnk</Link1>
<Link2>%ALLUSERSPROFILE%\Microsoft\Windows\Start Menu\Programs\Microsoft Office\Microsoft Excel 2010.lnk</Link2>
</TaskbarLinks>
</component>
</settings>
<settings pass="generalize">
<component name="Microsoft-Windows-Security-SPP" processorArchitecture="amd64" publicKeyToken="31bf3856ad364e35" language="neutral" versionScope="nonSxS" xmlns:wcm="http://schemas.microsoft.com/WMIConfig/2002/State" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
<SkipRearm>1</SkipRearm>
</component>
</settings>
<cpi:offlineImage cpi:source="wim:c:/win7_x64/sources/install.wim#Windows 7 ENTERPRISEN" xmlns:cpi="urn:schemas-microsoft-com:cpi" />
</unattend>
Thank you.