I just got my Transporter in today and am thrilled with it, but noticed that the top cover of it doesn't seem very securely attached to the chassis. If I push down on the front of the top of the unit lightly, the chassis cover gives under the pressure a few millimeters before it touches the inner chassis. This few mm of free space is enough that when I am playing music somewhat loudly, the top cover resonates slightly. Has anybody else noticed this on their unit or is it just mine?