Yesterday while I still had Pidgin 2.3.1, I downloaded a smiley theme from http://customize.org/gaimsmile/skins/54179 as I wanted to have the default protocol emotes. I was able to install it by dragging the decompressed folder into the Emotes folder in c:\program files\pidgin\pixmaps\emotes. It showed up in the list of smiley themes and I selected it in my preferences.
After I installed the new version, I did the same thing, but it doesn't show up in the list. Using the Add button doesn't work either. I also tried dragging the ZIP file to the smiley list in Preferences, but this doesn't install it either.
Why won't the theme install in Pidgin 2.4.0?
Never mind. I figured it out.