In the current (1.3.0) xorg xserver, the XEVIE can't be enabled.
It is disabled in os/utils.c, so that currently if you try to enable it in xorg.conf, X dutifully reports that it is initializing XEVIE as a built-in extension, but in fact it never does.
_X_EXPORT Bool noXevieExtension = TRUE;
_X_EXPORT Bool noXevieExtension = FALSE;
in os/utils.c the extension can actually be initialized.
Since this extension now is apparently required for gnome-2.18, it might be helpful to actually enable it.
Those are the defaults, they shouldn't force it off regardless of configuration. How are you determining that it's off, and how are you attempting to enable it? Please reopen when you reply.
Sorry - I think the only problem here was between the keyboard and the screen.