I've posted a launcher which I believe may fix the "Error loading pidgin.dll" issue that crops up on a small number of PCs. I've posted a test launcher that you can download and place in your PidginPortable directory. You'll then need to browse to the PidginPortable\App\Pidgin directory and rename pidgin.exe to pidgin-portable.exe.
This new fix works in conjunction with Pidgin's ability to work from a self-contained directory but preserves the ability for us to use the CommonFiles shared GTK with GIMP, the ability to use a GTKLegacy for Windows 98/Me/NT and the ability for the data to be stored in the proper place for PortableApps.com Format.
Please give this a test even if you haven't encountered the issue mentioned so we can be sure it works with shared GTK, legacy GTK, aspell, etc.