Having some trouble with 2 of 3 r-box's.

1 started acting up yesterday, the hash rate started dropping and after various restarts to cgminer and the computer, the pc eventually stopped detecting it.  The fan and red lights come on with the power cable, but nothing after plugging in the usb cable. 

It also appears that a chip to the right of the usb port is getting really hot, the pictures show this as the SILABS chip.

Tonight the 2nd one is doing the same thing.

Anyone have any thoughts or ideas on this?

Finally got my miners set up! Woo Hoo!

However, I have some support questions:

1) I am getting hardware errors on both units: one is running at between 1-2%, the other between 0.2-.05%. Is this acceptable or does it imply I have a faulty unit?

2) What is a safe temperature to run these at? My hottest one is running at 45C being clocked at 270. I'm working on getting a fan for the backsides, which seems to help.

3) Anyone know how to set temperature safety in BFGMiner? I understand you can set it to turn off if a certain temperature is reached as a safety mechanism, but I can't figure out how to set that up from reading the readme file.

Thanks.

I'm getting another new error!

One miner is being flagged as "Idle for more than 60 seconds, declaring SICK!" and a big red "sick" flag pops up. IF this continues, the flag turns to "dead."

Obviously, this is not a comforting thing.

Does anyone know what this error means/what causes it/whether to worry/and how to fix it?