Hi object limited to 6 items ????

Hello

I'm trying to build a controller, driven with the "Hi" object.

The controller itself will be a keyboard.
I rather use the Hi object (instead of key/key up) because i use two different keyboards (both as controllers) and i need them to be individual.

But there is a limitation i didn't expect : it seems to be impossible to press more than 6 keys at the same time, the "hi" object doesn't take more. Sometimes even less : for some keys (like numeric keypad or function buttons) it can be as low as 4.

Which is annoying ....

Would someone have a clue of a way to overstep/exceed this limitation ??

thanks