Hi, I recently got a PPOD HD500 and have a problem with the 'Overdub' feature of the looper.  When I try to overdub (after already recording the 1st loop) it will only record 1/2-3/4 of what I play.  I can tell when this will happen as it sometimes even seems to double what im playing, whilst I'm still recoding.  I press the overdub button as soon as I start playing so it's not due to me cutting the first partout manually.  Also sometimes, when I manage to get the overdub in, it will play back once, then stop for 4 bars or so, then play again.  Please could someone help as I am trying to practise looping the outro to 'On Impulse' by Animals as Leaders, as part of a solo guitar performance on Monday.  Incase your interested, the looper is set to 'Post' mode and '!/2 speed'.