We have several users who type both English and Hebrew. When they switch languages (either using keyboard hotkey or manually switching using the Language option on the taskbar), the output is always English, even though the language selector on the taskbar says Hebrew. The interesting thing is that if someone types on the host computer at the same time, the Hebrew works for them. But when the guest computer types, the result is only English.
I tried that, it doesn't work.
The crazy thing is that even though both the host and the guest are set to Hebrew, when I type on the host directly, it comes out in Hebrew. When the user types on the guest at the same time, it comes out in English. Very strange.
This is happening with more than one user and host.
One thing that confuses me slightly by your description, is when the Client and Host are typing simultaneously. The Host will always override the Client in these situations, unless the GoToMyPC setting for 'Lock Host Keyboard' is checked in the Host Preferences. Wouldn't the Client or Host side see that the person using that PC was currently active on it?