here finally is the complete answer to the problem of the waste ink tank counter reset for Canon i250 and i350 printers.

1. Disconnect printer from AC power (take out AC cord or power off your power strip). Disconnect USB PC cable from printer.
2. Press and HOLD the POWER button (untill step 7).
3. Reconnect power cord (turn on power) to the printer.
4. The indicator should be green.
5. Press and release the RESUME button , the indicator should be orange.
6. Press and release the RESUME button again, the indicator should be green.
7. NOW Release POWER buttons.
8. NOW Connect the printer to PC (USB cable).
9. NOW...I opened "Printers" and saw that a "copy" of my printer (i250 or i350) had been made. Make that COPY your default printer and all should work...It did for me.

Good Luck