Cubase 5 and Yamaha DD-55, not all notes triggering live


I seem to have a problem with my MIDI output when using my Yamaha DD-55. I’m running Cubase 5 on WIn 7 and the MIDI/Audio interface is an EDIROL UA-25.

Now if I setup a new instrument track and set the output to a Halionone drum kit it only seems to be triggering a MIDI note every so often. For example if I keep tapping the hi-hat pedal, the MIDI indicator shows every input coming in, it will record every note hit and play it back. But it will not sound every live hit, out of say 15 strokes I might hear 3 of them in real time. It makes no difference if I set the input to all midi in or the UA-25.

I have also tried using my casio keyboard to trigger the notes and the real-time comes out perfectly. I’ve tried using my DD-55 with MIDI-OX and it is picking up all triggered notes. So I’m not sure why Cubase doesn’t want to play all the triggered notes?

Any suggestions will be appreciated?