I live in the states so nothing weird regarding my layout. One day it worked and then another day it didn't.Do you live in a weird country? Weird as in "is the h on a different position on the localized keyboard layout compared to US International (it's between g and j on the middle row there)"? If that's the case you may have inadvertently switched keyboard layouts - If I remember correctly the keyboard shortcut for that is left <ctrl> + left <shift>, if not try the right ones.
Doesn't explain the mouse middleclick not working.
I noticed when middle mouse and H didn't work , if I scrolled up to see previous dialogue H would then work. But it i went to the current diaglogue it wouldn't. After my last post H worked whenever I wanted. Oh well, it works I guess haha.