Hi Dave. I guess I wasn't clear enough w/ my meaning. Sorry.
By 'slipping through the cracks", I'm not talking about letting a name expire. I was referring to forgetting/neglecting management, in this case, changing over to your own DNS. The default dns page is an affiliate style portal, ie ppc pg that is collecting revenue for the registrar, who's name server it is on. Again, the ultimate fault lies w/ the admin, who has not managed the name, however, the practice does seem a little underhanded on the registrar's part.
I guess it is more the feeling of indignancy I get when I discover a name that I had listed at Sedo/ Afternic and that I thought had been switched to their DNS (ie Sedo), has been sitting on the wrong server, (from my perspective), collecting hit's for the registrar who had gotten the drop for me.
Especially, after I swear that I changed the info because I know that during a login, I corrected the whois for the name and can't imagine not having changed the DNS. I had one registrar, DomainSite, where i had changed the DNS for about 40 names, that were low priority .names, went on my merry way and browsed to one of the names about 6 mos later, and it was still on DomainSite's DNS, collecting ppc income for them. After getting control over the names again, I was suprised to see that some of the names were getting 80-100 visits/ month and 3 of them were actually getting clicked on. They are .name but have fairly good short, single keywords I emailed Dsite and got a lame answer, something to the effect of, 'Oh, we didn't have their nameservers listed. We'll put them on" or up or something like that. I'll see if i can dig up the email.
Other than putting a page up that promotes their own site and services, or a for sales page w/ the owners approval, I think that registrar's might have a small conflict of interest going by monetizing someone else's domain name, for their own profit.