The problem is in the duplicated = signs, there should only be one. However, I cannot see why that would occur in an unmodified "active_users.asp". Please provide a link to your "active_users.asp" in .txt format for us to review.
This does happen in an unchanged active_users.asp. I sort it by fighting the symptoms, just adding this line before the SQL is executed (say, line 412, for you, garrigus):
ruirib is correct in saying that my active_users.asp page is not modified. Although, now it is because I have applied that fix. :) I'll keep an eye on it and see how it works. Thanks!
Carefree if you don't allow search engines to browse your forum, how does it get indexed? Or maybe you don't want it to be indexed? :)