Electronic – AVRISP MKII does not appear in AVRStudio 4 (latest build 4.18 SP1)

You really haven't given us any actual information to help you with other than you don't want an Arduino shield solution. What kind of power supply do you need? How many voltages, and at what current levels? Are you just powering the AVR? Do you need galvanic isolation?

I have successfully used National's LM5071 PoE PD controller in one of my designs. Depending on how you want to hook it up, it'll give you full galvanic isolation and multiple output voltages. My particular setup gives me 3.3V at 2A and a separately-isolated 5V at 1A. I "slave" an LTC3523 off the 3.3V to give me 1.8V and 5V supplies that aren't isolated from the main 3.3V supply.

Many companies offer PoE PD controllers. National, Maxim, Linear Tech, TI... Have you done any poking through their websites to see what's out there so you can narrow down your search?

EDIT now that I have more information from the edited question. :-)

TI's TPS2370 looks like a perfect fit. It's an 8-pin SOIC device that takes care of the 802.3af spec part and you can drive pretty much ANY regulator off of that. So a really simple supply would consist of the TPS2370 and something like the BD9001 (personally I like Linear's LT1676 but I don't think it has a high enough input voltage spec for PoE) from the previous answer. Two 8 pin SOIC devices, a handful of passives and a small inductor would get you what you're after.

I believe I may have found a two part solution for my particular problem. I currently own an Arduino Diecimila (which has the ATMEGA168 with the problem) and also a new Arduino Nano 3.0. I went ahead and flashed the Arduino Nano with the ArduinoISP firmware. I then picked up 3 28 Pin ATMEGA328P DIP chips for $5.00 each at the local electronics store.

I used the ArduinoISP to flash one of the virgin chips with the Arduino Firmware using the above link with a crystal. I plan to now flash one of the other ATMEGA328Ps with the High Voltage Programmer firmware. This chip along with a bit of wiring on a breadboard should allow me to reset all of the fuses on the original ATMEGA168. Once that is done, I will be able to use the Arduino Nano to reprogram the chip.

Since the ATMEGA328Ps only cost $5 each, my end goal is to setup one 328 as an Arduino ISP programmer, setup the 168 as a HV Programmer, keep one 328 chip in my current Arduino Diecimila (upgrade!!), and I'll have one left over for whatever. I can then either switch chips on the Diecimila or build out a real board for the ISP and HV Programmer boards.

I still have not tested the JTAG ICE MKII yet with a logic/oscilloscope. Not sure if it is the root of the problem or not. I will address this issue after I build the HV Programmer.

I will report back on the success/failure of the HV Programmer. I just need to go get a few more 1K resistors to pull it off. Anyone ever tried the HV Programmer? Any other suggestions? If nothing else, hope this helps someone.