Soooo, LJ stopped displaying my tags. So I asked them why.
Apparently it's because there's a limit to the number of tags you can have, and when you hit that limit it lets you know by no longer displaying them!
[Edit] Of course it never occurred to me that people might want to know the actual numbers!
LiveJournal has a limit of 1000 different tags per journal for Basic Accounts and 1200 different tags per journal for other account types. You are currently at or above the tag limit for your account, so you will be unable to create new tags until you have deleted enough tags to bring your total tag count below this number. In addition, while your total tag count is at or above the tag limit, you can use your existing tags, but tags will not be displayed on any of your entries that include new tags. For information about managing your tags, please see [
http://www.livejournal.com/support/faqbrowse.bml?faqid=226].