Unable to upload after working fine for months

I've been using a bar bones arduino board for many months, and just recently I'm unable to upload, even using 4 different computers (3 PC 1 Mac).

I am using a USB Bub from Moderndevice.com to interface with arduino. My symptoms are that upon upload both the pin 13 LED and the Logic LED on the USB Bub will blink quickly 3 times, then pin 13 will stall for a few seconds, then go back to the steady blink. After about 20 more seconds I get an error:

avrdude: stk500_getsync(): not in sync: resp=0x00 avrdude: stk500_disable(): protocol error, expect=0x14, resp=0x51

Typically the USB logic LED would blink fast 3 times, then go into a super fast blink during the data transfer.

Since it doesn't work on any computer, regardless of OS, I don't think its software related, but for reference I've tried both 0017 and 0018 versions on Windows 7 and Mac OS X.

My arduino is an atmega328 chip. At first I thought I fried the bootloader, so I ordered new chips, and same error. Also, and LED in pin 13 is blinking, indicating a functioning bootloader.

I'm 100% positive the correct board and com port are selected in the software.

I've tried setting the baud rate to 57600 in my FTDI driver settings, the arduino preferences file, and the hardware-board file.

I've made sure that "Set RTS on close" is selected in the driver setup.

I've tried reinstalling the FTDI drivers.

I'm at a loss of what else to try. Can the USB Bub go bad? Should I order another? Again I'd like to stress that this whole setup worked fine literally one minute, then nothing the next.

I've read through all the similar threads here, unfortunately none of those fixes help me. I'd appreciate any advice. Thanks!