Weird authentication problems on fresh install, then upgrade

Kind folks,

I ran into some weird problems with a 2.3 install, and spent many months beating my head against it. The general feeling seemed to be there were authentication and/or session and/or permission problems,but sessions tested fine, authentication was correct, MySQL was updated, permissions were wide open.

Ultimately, I gave up on trying to revive the old install, and simply started over, new folder, new database in parallel to preserve the old install. (I should say people including Suprspdr were offering incredible help, and then I had two back surgeries, a job interview, a move across the country and then had to come up with a new home network setup.)

So, on the new 2.3 install: This time I got all of six galleries in before the thing died; I went to upload a local folder, and it dumped me out to the main gallery page. Rinse, lather, repeat, repeat, repeat.

So I saw 2.3.1 had been recently released and tried upgrading. Whoops. Now I'm caught halfway between 2.3 and 2.3.1., where I can intermittently get authorized up to the Upgrade Core session (by running /install, then replacing login.txt, then going back to the upgrade). But the core upgrade page just stalls again, with a button click seemingly doing nothing.

I'm beginning to think my version of Vista is nuts, but I don't know why it would be.

Any ideas on where to go?

2.3/2.3.1 on Vista SP1, MySQL backend.

Earlier thread linking to earlier threads:
http://gallery.menalto.com/node/87937