B&K Reference 30 ...running hot, hot, hot

I recently had the latest firmware installed in this processor by B&K. (They are great to work with).

Now, I notice that the digital signal starts breaking up and the unit eventually (after ~ 1-3 hours) will not function properly, apparently due to heat building up. My unit is in a wall stack in a Mid-Atlantic rack and the is, apparently, not enough clearance above the unit and the next highest shelf to dissipate the heat.

Has anyone else experienced this with the B&K Ref 30?

I plan to move the unit to the top position of the rack to allow more ventilation of the heat it is generating.

Any comments will be appreciated.... Thanks.