Prion wrote:- QRecall cannot find the archive when I try to capture to the drive connected to the TC while logged out
That's expected; OS X can't mount a network volume unless you are logged in.
A Time Machine volume appears as a networked volume. Networked volumes require a user and password to mount, which requires that either you enter the name and password via a dialog or you save the name and password on your keychain. Both of those solutions require that you be logged in.
- when logged in, the capturing takes place normally, however, the log specifies that "Unable to read extended attribute data". This does not happen when plugging the drive directly into the MBP
That message says that the operating system reported that a file or folder has extended attributes, but when QRecall tried to read them it returned an error instead. You might trying repairing the volume and see if that makes any difference.
The file that encountered the problem, the name of the extended attribute, and the error returned by the operating system are included in the details of the message. If you need help deciphering the cause or its implications, send a diagnostic report (Help > Send Report) and I'll take a look at it.