Left some open high-impedance inputs on the PCB? Nah...no one is that stupid.
As an EE of 45 years experience I can assure you that would not be a problem. Writing code for nearly as long would lead me to believe that it was a software issue concerning radio usage (both phone and GPS) and the percentage of time that the device was "awake" to the user. This fundamental clock determines the amount of delay you are willing to tolerate between the time you touch the device and the time it wakes up. This is critical in battery usage.