I think what happens is that if you specify 10-bit precision it doesn't mean that the two low-order bits will be zero. If you have 10-bit precision you should clear the bottom two bits. The result of 26.06 from probe 5 just means that the bottom two bits happened to be 01 (corresponding to .0625 degrees C) which you should have cleared so that the result was 26.0C.
Pete