I'm having problems with the latest alpha Post-Thumb and WP 2.6. This is the warning I was getting:
Warning: unserialize() expects parameter 1 to be string, array given in /www/htdocs/w006dc1d/travelogues/wp-content/plugins/post-thumb/post-thumb.php on line 83
I tried switching back to the stable version, but then only my category images were displayed, so I switched back to the latest alpha and even though I had deleted the cached images in the meantime, all images were displayed properly, except the one from my last post (first post after upgrade to WP 2.6). Here the category image was used.
I had a look around. Here on the forums someone suggested (for another plugin) to just delete the unserialize bit out of source code. I tried that, with the effect that now the post thumb for my last post has been generated and is showing up, but none of the other thumbs are being shown. You can see it here: http://travel-junkie.com
I then put the unserialize bit in again, but that didn't change anything.
I asked for support already on the Post Thumb forum, but it seems that Alakhnor is on holiday or something like that.
I'd really appreciate some help here, cause right now my frontpage is a mess!