Thanks so much for this plugin, I love it!
I recently updated my site to require SSL admin, and I could no longer upload files using WPPA.
I was able to fix it by replacing get_option('siteurl') with get_admin_url() (and fixing up the relative path) in wppa_upload.php. It's now working for me.
For example, line 68 (in v3.0.2) went from:
<form enctype="multipart/form-data" action="<?php echo(get_option('siteurl')) ?>/wp-admin/admin.php?page=upload_photos" method="post">
<form enctype="multipart/form-data" action="<?php echo(get_admin_url()) ?>admin.php?page=upload_photos" method="post">
I think I found 5 places where this code was. Not sure if there's a better way to fix it, but that at least worked for me.
Thanks again for the plugin, I really appreciate all your work!