Chris,
I had a similar problem but different enough that I hesitate to mention it. For me, it switched to Chinese and seemed to affect other programs as well, although the problem always started when I was running Emacs.
This may not be your problem but maybe my solution will help you or someone else.
My problem turned out to be with Windows XP and not with Emacs or JDE. Some language packs on Windows XP steal key combination (such as C-SPC and others) and use them to switch input language. If you have other languages installed on your Windows machine, that may be the problem. I solved it using a key-remapping program called AutoHotKey which stole the key combinations back.
Cheers,
Benji Shults
