I cant read keyword posts after receiving email notifications

[Matt O'Rourke]

I can no longer view 'keyword' posts in the forums. I get an email notification about new posts containing keywords, yet when I go to the forum and sign in, I get a message stating 'you must be signed in to do that' or something similar.  I have signed out, signed in, scrolled through the forums to try and find the posts.  
One other question:  Why when I search keywords in the forum are the posts so random?  One from 6 days ago, the next from 5 years ago, then one from 19 minutes ago....