The event.fix() function (line 2746 in jquery-1.3.2) change value of event.which, and thus broke detection of MANY keys.

For example, on keypress() in Opera-10,

key Up return: keyCode=38, charCode=undefined, which=0

key & (Shift+7) return: keyCode=38, charCode=undefined, which=38

So, only way to distinguish Up and & is check event.which value... but jquery's event.fix() make event.which=event.keyCode.

As workaround one may use instead of

$("#input").keypress(myfunc);

this code:

$("#input").each(function(){
  this.onkeypress=myfunc;
});