This is basically a repeat of this thread (but it's read only now, so I couldn't respond on it) - http://silverstripe.org/archive/reply/4363 that was never resolved.
In the CMS, I've used this $f->removeByName("Domain(s)"); to get rid of the domain(s) field in the Behavior tab, but I'm left with "Use this page as the 'home page' for the following domains: (separate multiple domains with commas)". I've tried removeByName for that, but it doesn't work. Anyone know how to get rid of this?