Yah I saw this... I'll give a bit of an explanation for those interested...
Every member's name tag (or member tag as I refer to them) is generated upon login and cached on the server's hard disk.
It's a resonable amount of work to generate a member's tag with the profile star, proper colour and bling rating. When you consider that in the forums, there can be up to 100 member tags displayed PER PAGE, in addition to the online list (another 200-500), it's alot of work for the server to re-render each tag on every page load.
So when you login, the server generates your tag and saves it. Then, anytime your name is needed somewhere, the server simply includes the pre-generated tag. All the parts of the site I've written does this, as viewable in the comments, forum, profiles, messages. Older parts of the site that I havn't had time to re-write don't, (videos, pics, articles, reviews, links, etc..).
The advantages are obvious, not only is it less work for the server, but anywhere this mechanism is used, your name is displayed with the colour and bling rating and profile star.
The problem with names dissapearing was that the hard disk filled up 100% and there was no longer any room to write the member tags. So as new members logged in, their tag was not generated and instead an empty file was created. This is why the online list and forums had missing names.
I'm too lazy to come up with a new signature so now it's this.