Troubles With Roland Vg-88, when you use section like brass,bowed Options

Hi friends,
i need help to solve my troubles with vg-88.
Didn't have you notice that when you use the instruments like BRASS , BOWED , SOLO, DUAL ... (the synth section) the decay of the sound is not linear , but at about the end
there is a unwanted trembling and metallic sound.
At least MY VG-88(updated at version 2 too!) DO THIS !!

PLEASE SEND ME YOUR SUGGESTION AND OVERALL LET ME KNOW IF YOUR VG-88 INSTEAD WORK WELL ... 'CAUSE MY ROLAND SERVICE CENTER SAY THAT DON'T NOTICE NOTHING OF STRANGE .... AND IT NEED THAT SOME GUITARRIST OWNER OF VG-88 CONFIRM WHAT I'M SAYNG..

Thank you very much

Dimitri from Italy
frondizi1@interfree.it