Yamaha DTXpress/DTXplorer/DTXtreme

Dear all

Hope to get some help from you folks.. I have a DTX3SE for about a
year 
now and has been having fun until recently. Has been getting
'dropped' 
hits on the snare pad esp when i play fast eg 16th fill or practising 
rudiments. This happen on the toms pads as well but less often. Tried 
switching the tom pad with the snare but the same problem
persist...so 
i reckon it is not a snare pad problem.
Also 1 0r 2 of the fast beats comes through very loud (as if at max 
volume) with no change in my hitting force. Brought the unit back to 
yamaha service centre (in Singapore) but was told nothing wrong!

Any one had the same problem or solutions?

Thanks a lot.


david