It’s been a long time since we last had an active Windows-based developer. Consequently, GIMP has accumulated a plethora of bugs specific for that operating system. As much as we’d like to provide a smooth user experience for Windows users, we simply do not have the required human resources.
Hence, if you are an experienced Windows-based developer who is interested to help GIMP become a first-class citizen in the Windows world, please get in touch with us. Our main communication channels are the gimp-developer mailing list and IRC. Here is the list of all reported bugs for the Windows version of GIMP.
If you go for IRC, we recommend sticking there for several hours, since we are mostly Europe-based, and you maybe aren’t in the same timezones span. Most development talks happen on IRC anyway, so staying online helps the communication.