Yes, removing that entry would be a good thing to try. You may need to ensure that the correct display drivers are being loaded.
If you're only new to the unattend.xml configuration method don't feel discouraged by these small teething issues. It may take a few days to get perfect, but once it's set up it sould save you plenty of time with your Windows 7 installs (and SOE).
You may also be interested in:
the autounattend.xml file i use, it doesnt include any display configuration and always uses the max allowable resolution: Windows 7 Autounattend Example
these notes on customising the default user profile in Windows 7 (it's not as easy as Windows XP was ): Customise Windows 7 Default User Profile
or if you're using ConfigMgr / SCCM : Windows 7 Default User Profile with ConfigMgr