Did you select the 8 MHz homebrewino board and upload the sketch again? If you select a 16 MHz board and upload to an 8 MHz board it will run at half speed. The calls to "delay()" and "delayMicroseconds()" will be slow and that might be enough to screw up the receive timing.
The code (DHT-sensor-library/DHT.cpp at master · adafruit/DHT-sensor-library · GitHub) measures pulse widths and looks for a count > 6. Perhaps that value will have to be adjusted down because the code outside the "delayMicroseconds(1)" is running slower.