PLEASE NOTE
For those of you who may have already downloaded this block, I made a much needed improvement (albeit simple). You should go in and make this change:
ORDER BY RAND() LIMIT 1
to
ORDER BY RAND(NOW()+0) LIMIT 1
Apparently, in 3.23.5x anyhow, mySQL rand, without some kind of seeding is not so random, and the first record that met the where criteria in the database comes up 75% of the time.
With this change, it seems to change every time. Sorry about not realizing that when I first wrote it.
Can someone email me and tell me how to update the version in the downloads section? (It wasn't obvious to me) - thanks