Emu XL-7 & MP-7 User's Group

I have a recurring problem that is really buggin' me!
Sometimes (not all the time) when I select a track then go into grid 
record mode, hit play, select a pad then switch on the triggers for 
the beats I want, the wrong sound will play.  Usually I get the sound 
assigned to the pad one octave above the one I selected.  If i change 
the transpose this does not help.  However, if i change the pattern 
to say the previous pattern preset and then back to my user pattern, 
the problem goes away.
Did this make sense?
Anyone know what is going on?
Thanks,
grimley.