Issues programming Polulo 3pi with 328

I'm having trouble communicating between my Arduino IDE and my Polulo 3pi robot, which uses an ATMega 328p (which I believe is equivalent to an ATMega328). I'm using an AVRISP mkII, and I already checked to make sure that I installed the driver, which I did. I have my robot powered on, and all of the indicators on the ISP check out (green lights all around, no magic smoke escapes when I connect one end to my USB port and the other to the ISP-6 slot). I'm using Ardunio 1.0 and my OS is Windows 7. I am remembering to hold down the shift key when I hit the "upload" button, and I did change my "boards.txt" file to reflect the slightly changed board.

When I go to upload my example program, Arduino IDE spits this:

Binary sketch size: 1594 bytes (of a 32768 byte maximum) avrdude: usbdev_open(): did not find any USB device "usb"

back at me. It seems to me that it is not recognizing my USB device, which seems pretty inexplicable to me. Windows recognizes it, yet Arduino doesn't. Help, please! I feel like it's something really stupid I haven't thought of yet.

Damn that was six yearsa gao, I have the same problem and N ot a damn thing.