My nephew ported his Vodafone number to Skinny several months ago.
His girlfriend and I are on Vodafone and we get a number invalid or not currently active when we try and call him. My son who is on 2Degrees is able to call him.
Reading old forum post sounds like a porting issue.
@MikeHales @Linux I'm about to call a CSR to report this. Is there anything specific I should tell them?