moveMessages() produces an IMAP error

[matadan]

I am trying to move a message from the INBOX into another folder but I get this error:

7 BAD Unrecognized UID subcommand

[brian-schick]

We're encountering this error as well. I've confirmed that both toFolder and fromFolder exist and are populated, that the wrapping moveMessages(fromFolder: toFolder: uids:) gets the message uid's, and that the error is thrown from the C mailimap_uidplus_uid_move(…) method. The returned error is simply "unknown". Disturbingly, we've found that replacing a valid fromFolder name with a bogus one makes absolutely no difference, and all wrapping assert() checks behave identically.

Is there any info on how to resolve this?