avr-nm gives u addresses like this:
00810000 T __eeprom_end
00800060 T _edata
00800060 T _end
i just had a look at this:
and they say it has 8KiB SRAM...
and the Servo class has just 3 bytes...
what if u use just 1 sensor?
maybe more observations help to find the root of the bug...