Sysprep - keyboard and mouse will absolutely NOT work

I'm not new to sysprep, but a recent run-in with this tool for imaging computers has left me extremely frustrated.

I have prepared an image, sysprep'd the machine, and added all the drivers to a folder on the local drive - updating the "devicePath" registry entry. Sysprep is set to use minisetup and skip the welcome screen.

Everything works fine when deploying this image to our Dell Optiplex 745s, 755s, and 760s, but when I deploy it to a Optiplex 620, the keyboard and optical mouse do not work, no matter what. It doesn't matter what USB ports they are plugged in to, or even if I unplug and plug them back in when sysprep stops to name the computer. I don't have ANY input capabilities. The light on the mouse doesn't even come on.

Can anyone shed some light on why this could be happening?

Below is a copy of my sysprep file:

;SetupMgrTag
[Unattended]
    OEMSkipEula=Yes
    OEMPreinstall=Yes
    DriverSigningPolicy=Ignore
    UpdateInstalledDrivers=Yes
    UpdateServerProfileDirectory=1

[GuiUnattended]
    AdminPassword="xxxxxxxxxx"
    EncryptedAdminPassword=NO
    OEMSkipRegional=1
    TimeZone=20
    OEMSkipWelcome=1
    AutoLogon=No
    AutoLogonCount=0

[UserData]
    ProductKey=xxxxxxxxxx
    FullName="xxxxxxxxxx"
    OrgName="xxxxxxxxxx"
    ComputerName=

[Display]
    BitsPerPel=32
    Xresolution=1280
    YResolution=1024
    Vrefresh=60

[SetupMgr]
    DistFolder=C:\sysprep\i386
    DistShare=windist

[GuiRunOnce]
    Command0=c:\windows\system32\cleanup\cleanup.bat
   
[Identification]
    JoinDomain=xxxxxxxxxx
    DomainAdmin=xxxxxxxxxx"
    DomainAdminPassword=xxxxxxxxxx"
    MachineObjectOU = "OU = Client Machines,DC = xxxxxxxxxx",DC = xxx"

[Networking]
    InstallDefaultComponents=Yes

[SysprepMassStorage]
    *PNP0F03="%windir%\INF\MSMouse.inf"
    *PNP0F0B="%windir%\INF\MSMouse.inf"
    *PNP0F0E="%windir%\INF\MSMouse.inf"
    *PNP0F12="%windir%\INF\MSMouse.inf"
    *PNP0F13="%windir%\INF\MSMouse.inf"
    *PNP0300="%windir%\INF\keyboard.inf"
    *PNP0301="%windir%\INF\keyboard.inf"
    *PNP0302="%windir%\INF\keyboard.inf"
    *PNP0303="%windir%\INF\keyboard.inf"
    *PNP030b="%windir%\INF\keyboard.inf"
    *PNP0343="%windir%\INF\keyboard.inf"
    *PNP0344="%windir%\INF\keyboard.inf"
    *PNP0345="%windir%\INF\keyboard.inf"