I've seen a fair amount of breakage recently in my apps that connect
to the Flickr API that depend on authentication. Not sure what the
root cause is, but I'm pretty stuck and could use some help.

http://www.scripting.com/2007/11/12.html#getFrobProb

It could of course be the result of me not understanding frobs and
tokens, though the code did work before.

I tried an experiment with the Flickr API Explorer and it failed the
same way my code is failing, with various messages that say I have an
invalid token or frob.

Has something changed recently behind the Flickr API?

Grasping at straws here, I've put in about 24 hours so far trying to
figure out how to *approach* the problem, but haven't gotten anywhere.

All this code used to work, for months...

I just tried uploading a picture in some production code, and it's
broken too.

Any help would be much appreciated.

Dave