I've just registered my command to show find/replace dialog on Ctrl+F/Ctrl+H.
However, syntax editor does not call underlying execute method of ICommand.
This issue is easy to reproduce, just go to syntax editor sample browser and select Edit Actions example.
There is "Bind to Ctrl+M" button to click. Then obviously, Ctrl+M should work, but it does not.
BTW. There is also problem with this web site, Create Thread as well as Complete Order buttons do not work in IE11 (and you must know, that IE11 is the last browser to support Silverlight, right?).