There doesn't seem to be anywhere to post this query, except here, so it will probably get buried before answered!
Why is it, in the members list, there are so many, even regular posters, who are listed as last visit in 1970??
This seems to be due to one of the cross-modifications we have put in place. However, it is nothing to worry about at present time. I suspect that it has something to do with the fact that we are now heavily compressing the code in order to speed up the rendering and delivery of pages as much as possible. It could also be an issue introduced in the latest version of vBulletin. Nonetheless, it is a problem that will not affect anyone in a major way in the future, and may simply be a trade-off for some of the modifications we have had to make.