he keeps asking me to explain why my advisor can't do it, and he won't do it until my advisor says it's OK, and my advisor is not answering emails.

Can you e-mail your Chair or Director of Graduate training about the problem, not in a mean way, but "my advisor is not currently available and I need to load these things as part of my job search." They may be able to provide enough permission to bypass your advisor.

I'm the director of a graduate program, and I get requests like this all the time. Faculty are flaky. It's expected.

ARGH! Faculty often suck. And once they have tenure, there isn't a damned thing you can do about it. sometimes I think we should get rid of it, but then I remember all of the cutting edge research and theory that might not have moved forward if people had been afraid for their jobs.

Oh, I've been here, as the professor asked to do it. I know that you are in a bad position (and totally legit in your request), but I've been burned by shady students trying to do an end run around requirements through my kindness.

Yeah, I know. I forwarded him an email from my advisor where my advisor said that he would endorse it if he could, and I told this professor that he could ask my advisor about it if he wanted, but that my advisor hasn't been answering my emails lately so I'm not sure how to get in touch with him.

Will the advisor answer emails from his colleague?

I have no idea.

Oh, I wasn't clear when you said that he hadn't been answering emails. I really should have said will the colleague email him and see if it's okay? He might answer an email from a colleague where he wouldn't answer yours.

I don't know if he'll answer emails from colleagues. I've heard other professors complaining about him not answering emails plenty of times.

If he doesn't answer the colleague's email, then the guy will figure out why you're asking him to post the paper instead of your advisor.

If I wanted to do some kind of end-run around my advisor, this professor is probably the last one I'd pick. It's just that, as far as I can tell, he is the only one in the department who is actually allowed to endorse people. (There are two other professors who ought to be allowed to, but all their papers are cowritten and registered under another author's name, even though the system allows you to register multiple authors.)

If I wanted to do some kind of end-run around my advisor, this professor is probably the last one I'd pick.

Oh, I wasn't trying to imply that _you_ were doing anything wrong at all, I hope that it didn't seem that way.

Yeah, I know. I was just saying that, if this professor is at all self-aware, he'd know that he's not the guy someone would try that with.

har. You're asking a lot for (some) faculty to be self aware.