i'm sure you'll be glad to know i solved the mystery!

apparently, the whole issue with the sidebar going missing was because of problems with the "<div>" tags in the html of one of the posts. i figured it out with the help of a little googling.

(yeah, yeah, i could have done an update to the other post or just deleted the doggone thing, but sue me, i'm shamelessly padding my post count for the year.)