Hmm. flashrom does not seems to detect the chip, time to hook up a logic analyzer to see what is going on. 

mm@lapos:~/Projektek/flashrom$ ./flashrom -p usbblaster
flashrom v0.9.9-r1954 on Linux 3.13.0-94-generic (x86_64)
flashrom is free software, get the source code at https://flashrom.org

Calibrating delay loop... OK.
Found USB device (3923:7514).
No EEPROM/flash device found.
Note: flashrom can never write if the flash chip isn't found automatically.

It seems that only configuration data is stored in the flash: if removed the screen blanks HW-err: flash message.