I am trying to sign a key that contains a photo UID. It is not the last UID, and there are revoked UIDs that follow it. Following the revoked UIDs are more valid UIDs.
Because PIUS does not count the some UID, it tells GPG to sign the revoked UID which bails out. The key in question is 0x6EDDD207FCC5040F.
The layout according to GPG is:
(1) valid, primary
(6) valid, jpeg image
When I run PIUS, it outputs:
UID 8 (<email address="" for="" UID="" 9!="">): ERROR: GnuPG won't let us sign, this probably means it can't find a secret key, which most likely means that the keyring you are using doesn't have your public key on it.
I'm assuming that it's the JPEG UID that PIUS is skipping, as it doesn't seem to send out any signatures for it.