amp pop - need help

just purchased a McCormack DNA-1 Deluxe. While the sound quality is greatly improved - better stereo separation, deeper bass, less harsh highs, improved dynamics - I have noticed the amp gets quite hot. After just a few hours the heat sinks are hot enough to be quite uncomfortable to the touch. Worse, though, the amp makes a popping noise as it heats up. Sounds a bit like metal expansion. . .the wife says it sounds like the last kernel of corn popping in the microwave.
Not sure if this is an issue but it sure is a big change over the previous amp that would run all day without overheating.

Any ideas?
Contact McCormack, they should know. The audiogon home page has a link to manufacturers but here it is,
Something wrong there. My DNA 0.5s always ran relatively cool, cooler than the 1.0s for sure. You will probably need to go to SMcAudio for service; while its in, spring for an upgrade. Really improves the amp.