Hello,
I'm using GIMP Portable 2.6.6 on Windows Vista (Chinese version), I noticed there is a strange character at the bottom of window (Please see the screenshot at the below). It doesn't cause any function loss but it is somewhat annoying. (I didn't install additional locales and I'm using LANG=en_US)
That's a GTK issue when you have Chinese language support installed in the OS. It happens on my English copy of Vista within a local install of Pidgin, too.
Sometimes, the impossible can become possible, if you're awesome!