Grungebuster mat and Sony 999ES

I have the Sony Modwright 999ES and was told by the people at Herbies that it will work fine in this trasport.Well i tried it on two Audio discs and then a DVD disc and i definitely feel it was a great tweak and i became a believer.Then i stuck it on a second new DVD(16 Blocks with Bruce Willis) and the DVD started freaking out in my transport and i could not get it to stop and the power would not shut off and i had to physically remove the power cord to get the thing to stop.YIKES!!!!The disc is fine itself with no scratches and plays flawlessly without the matt adhered.
I was bummed but thought i had it on wrong possibly and did it again paying close attention to placement and making sure it was solidly adhered and it did the exact same thing again.Needless to say i am worrying about damaging my unit with this type of treatment and was wondering if anyone else experienced this alarming difficulty with the grungebuster 2 and the Sony 999ES transport?Am i doing something wrong?Are there certain discs to watch out for and if so which ones?Anybody got the scoop on this?

thanks for your help

Craig