Reset pin crashes ethernet shield

Hi all,
When I want to reset the standalone Arduino(+Ethernet Shield), then when restart the ethernet shield does't work. It seems the ethernet shield crashes.
I don't understand why, if I do the reset through the reset button on the Arduino board, it works ok.
I need to put a new button far the Arduino, to make the reset easier, because the Arduino is to high (3 about meters, in the roof). But, as I mentioned, when I connect a button through the rest pin, the ethernet shield crashes...
Do you think I have to connect a pull up resistance to the reset pin?
Or what?
Many many thanks, I will be awaiting for your reply,
Best regards,

Please describe your hardware more clearly, and where this other reset is wired up.

We are controlling 3 CC motors of 48V, 6 limit sensors and some relays that triggers LED lights.
When we solder a wire to the terminals of the button, or if we connect a switch to the reset pin (going to ground), in both cases the arduino crashes.
It doesn't depends on the cable length, if I connect it with a small piece of metal, is the same...
I'm actually confused, I don't understand what is going on,
I hope you can help,
Many thanks! Best regards

The arduino and the shield both have 10k pullup resistors already.
I don't see why your remotely connecting reset to Gnd would bother anything unless the wire is picking up a lot of electrical noise.
You could try some isolation - for example, a switch at the far end that would energize a relay, the relay contacts would then connect reset to Gnd.

In times past there has been discussion of a power up race between the arduino and the Ethernet shield when power is interrupted. The below may have a software fix for such a condition.