Sudden unreliability with my network-enabled Arduino project [SOLVED]

Shown below is my device, installed in my permanent location, and circled in red. Also notice the 3 fluorescent lights, which I believe is on the same circuit.

This image shows where the Ethernet cable crosses the electrical cable for the lights. I've always understood that as long as they cross like this (are perpendicular), it's ok...you just never want to have them running in parallel.

I currently have it connected to an extension cord (orange, hanging down) which as I mentioned in a previous post, goes to inside my house, and it works fine when connected like this. However, when I have it plugged into the black power strip (where I want it to be plugged in long-term/permanently), I have the problem previously mentioned.

Anyway, in answer to your question, dswan75, the ethernet cable does run within a couple of feet of the middle lights, but I don't know if it's an 'air'/'airwave' problem...it seems to be inside the actual electrical lines themselves that's going into the power of my device wouldn't it? Because again, that ethernet cable never moves through my testing.

@Hugepedlar - I don't know if I have a battery that could power it for very long...a 9V wouldn't last very long, would it?

I don't know how to check for memory leaks yet. I still tend to think it's a hardware issue, but I will look into it. Yeah, I've been thinking of hooking it up to the Arduino serial monitor, but have been putting it off as I will have to modify the circuit in order to be able to do that I think.

I'll see if I can find something like that to put the project in.

Well when I had it in my room, it did work for weeks if I remember right. And when I have the device in the garage, and the power running to inside the house (in my room specifically), it worked for weeks also.

Thanks everyone so far...maybe the pictures will reveal something I'm missing...