Please describe the problem:

When selecting a short sequence of numbers (4,4.1,4.2) and then extending the selection to extend the sequence it will go fine for a number of items and then will have rounding errors such as 5.49999999999999 instead of 5.5. Some testing has determined that this problem can return to normal operation even with the rounding errors in the middle of the sequence. It is not guaranteed to be the same each time.

Steps to reproduce:
1. C7 = 4; C8 = 4.1; C9 = 4.2
2. Select C7 to C9
3. Extend from the bottom right going downwards. 


Actual results:
The extended sequence worked fine until it got to 5.2, which it was 5.20000000000001, 5.30000000000001, etc. In another instance, it did it at 5.5 with 5.49999999999999, 5.59999999999999, etc. One more instance repeated this but went back to normal for 10.1.

Expected results:
It should have been 5.2, 5.3, etc.

Does this happen every time?
Every time some sort of rounding error occurs, no guarantee as to complete repeatability.

Other information: