I may have discovered what the problem with PGP posting to LJ is.
Just for kicks, I just tried posting an entry using inline PGP, as opposed to OpenPGP (PGP/MIME) that I usually use. And it worked.
Now, the thing that I'm having trouble understanding is, why do OpenPGP e-mails result in an error, when they *used* to work. Because I used to be able to post with OpenPGP style signed e-mails.
Oh, well. If it works with old-style inline PGP, it's at least better than nothing. (If this gets through on the first try, then it'll mean that they fixed the OpenPGP signed posts problem (hopefully!)).
[Update: It worked! Looks like the LJ coders have gotten the PGP posting bugs fixed. This totally rocks. ;-]