Can no longer upload ANY sketches to Arduino Mega 2560 - timeout at upload

The LED blinks continuously at roughly 10Hz. Pressing the reset button simply interrupts the blinking. When i disconnect and reconnect the power, the LED blinks twice at roughly 2Hz before going back to its continuous 10Hz blinking.

I guess I'll get back to you once I've figured out how to burn the bootloader. Would anyone be interested in seeing the code that I believe ruins the bootloader? I would post it regardless, but it's quite lengthy (5 .h files, 2 .cpp files, 1 .ino file).