Hasselhof, a DG certificate can be obtained with a couple of hours work on the internet. If a company is using that as an excuse not to interview when everything else points to a suitable applicant then it speaks volumes about the company and its standards.
The requirement for a DG certificate every 2 years is farcical and is nothing but another ridiculous requirement that has little value in practice. Certainly it should be required initially but every 2 years thereafter?