OK, someone who is much more familiar with Insecure Exposer showed me this little doohickey:
Tools | Internet Options... | General, then access the Settings... button, and set the "Check for Newer Versions of Stored Pages (which is Micros~1-esque for "Cache Refresh", apparently) to "Automatic" (from its previous setting, which was "Never").
LRPDs and other forum behavior returns to normal.
Gad, I hate working with Micros~1 shit!!!