Multitouch files.... what I am doing wrong?

I have uploaded the multituoch file with a basic setup(I just have added basic logics, nothing else, I know this is not the way…) . There are two file in there. what happens is That if I press two keys at the same time and then lift finger from one both keys stop working and then, still with that one finger on the key, if I use another finger again, it doesn’t do anything. Please some one help me it’s a really small file and nothing much. And logics are very simple. It can be a bug as well.
Multitouch (107 KB)