Speakers 'Squeal' when scanning for codes and can't access modules

Hey guys.

When auto-scanning for error codes, the radio will turn off and give a short squeal through teh speakers, and turn back on. This happens about 7 or 8 times during the scan. Anyone know if this is normal, or had it before?

Secondly, VCDS can't access modules 37, 56, and 77 which is Navigation, Radio and Telephone. I also can't access some of the central electrics module (it seems to scan okay, but won't let me do much adaptation). Anyone know why this is?

Thanks