are you using s2? apparently you need to to have your own tags work... if you already are then i don't know, because s2 sucks and i haven't tried it yet. i can still get to other journals' tags though. you might have a special lj problem all your own! (yay! :P ) or the journals you're trying to get to haven't enabled s2. try fandomhigh's tags, i can get to those.