Monolithent , thanks for the clarification. Then the most likely culprit would seem to be a faulty power supply.
adamdegraff, I'd call tech support ASAP to have them arrange to have it repaired.
Honestly, I'm not familiar with the 16.4.2 but it sure sounds like it could be heat related. Does it utilize a fan ,and if so does it seem to be working properly, or maybe a defective temperature sensor etc... Purely conjecture on my part. Regardless, it sounds like sending it in for repair is your only option.
Chuck did you try to register your copy of Studio One Pro after creating your account on this board?
Steps:
1) Login to your account (Found under technical support menu item)
2) Choose Software Registration and enter your key code at the prompt.
3) After registering the software go to my software
ADM3 ,
I totally agree with your point about Pro Tools plugs being resource hogs! That is one of the reasons I chucked it (Pro Tools 9). Avid is also slow as molasses with supporting new OS's like Lion!
The 400 firewire shouldn't be an issue. I'm running a 27" iMac quad core interfaced to a MOTU Ultralite mk3 (fw 400 ), and have no issues with latency under Lion and S1 1.6.5.