To correct this, the "options.dopt" file needs to be deleted.
To do so, open up a Windows Explorer, select Tools/Folder Options, click on the View tab and check the option "Show hidden files and folders".
After that, the file can be found on XP in this location:
C:\Documents and Settings\(user name)\Local Settings\Application Data\Darksiders
For Vista and Win 7 it can be found in this location:
Once the file has been deleted, Darksiders will start up using the default resolution.