Tried to post a thanks a moment ago, but doesn't look like it made it through. Anyway, BIG THANKS for the help!! I had, in fact, tried the P4 renderer before I even posted my question, and it still had some (though not as much) artifact. But changing all the squares to one-sided fixed things in a jiffy! I really appreciate the swift help! I already had wasted hours on this little snafu.

Cheers!

J