What you see in irw is correct. It SHOULD be sending buttons twice. (So long as the show up as 00 and 01 right before the button name)
The problem you're having with Boxee is different. Boxee's repeat delay is too short, IMHO.
The best thing to do is raise Boxee's repeat delay:
In ~/.boxee/UserData create a file named: advancedsettings.xml
In it put this:
Code:
<advancedsettings>
<remoterepeat>1000</remoterepeat>
</advancedsettings>