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

Here's a very odd Bug ive been having. 
One of my patterns has a distorted guitar chord in it. I turned the 
sustain and release knobs far to the right so that when I hit the key 
it slowly fades away, (just like a rock guitar big strum). Sounds 
great. However, after my pattern has been playing for sometime the 
sustain and release on that preset randomly revert to being short, 
ending the guitar hit where I let go of the key. It seems to be at 
random, and it also seems to be worse when other tracks are playing, 
I have tried erasing all controller messages and resaving the preset 
with the sustain and release turned up but to no avail. If anyone has 
encountered this problem, or more importantly the solution it would 
be greatly appreciated. Thanks.