something worng in dht11.cpp

[2014c2g1]

I test program ,but always wrong.
I edit dht.cpp .
in line 82.
uint8_t sum = bits[0] + bits[2];
I thing is
uint8_t sum = bits[0] +bits[1] + bits[2]+bits[3] ;
and the program work.
so,I think bits[1] and bits[3] not always 0.