Super Cache 8.5 stopped working suddenly

Super Cache has been running along in my two sites (both standard WP installs) with no problems until suddenly caching stopped working on both sites at the same time. I’ve been running the latest trunk builds for both sites (via the “Stay Updated” link) and Super Cache hasn’t had a problem yet until now. Funny thing about it is that the plugin was working fine on the latest build (9909) and all previous builds before it. It was working fine this morning until around 1:00 PM when caching on both sites just quit. This is what I’m getting at the bottom of the source of the main page and single post pages:

<!– Dynamic Page Served (once) in 1.340 seconds –>
<!– super cache –>

Just 2 hours prior, the pages were being cached just fine, loading in less than half the time (about .4 secs) with only 15 queries or less. No changes were made on my side of things at all and both sites quit at the same time.

Pages are being cached for both regular caching and super caching (seen via FTP), cached pages are incrementing normally as seen in my Admin’s Super Cache page and the plugin is installed correctly (as it always was).

I’m stumped…any ideas?