problem with DS18B20

@graf don't worry about the code formatting, it's fine :).
I tried the things you requested, and I got the following results:

with version 1v43
I indeed get 40 as a result, and the sensor is working as expected.
The result of process.env is

={"VERSION":"1v43","BUILD_DATE":"Dec 10 2013","BUILD_TIME":"11:59:35","BOARD":"ESPRUINOBOARD","CHIP":"STM32F103RCT6","CHIP_FAMILY":"STM32F1","FLASH":262144,"RAM":49152}

with version 1v46
ow.search returns [], thus the result of the next queries is undefined and 0. The result of process.env is

={"VERSION":"1v46","BUILD_DATE":"Jan 24 2014","BUILD_TIME":"17:28:16","BOARD":"ESPRUINOBOARD","CHIP":"STM32F103RCT6","CHIP_FAMILY":"STM32F1","FLASH":262144,"RAM":49152}