I recall from writing some VB programs that VB rounds differently from pure mathematical rounding in the case of a value lying exactly between 2 values (e.g., 10.5). You can read about it for VBScripting from MSDN Library here
In a nutshell, VBScript will return the nearest even
number to the value that is to be rounded. For example, 10.5 rounds to 10 rather than 11; 11.5 rounds to 12.
If this is the case, the poll result rounded to 1 decimal place would be 10.5; applying the above algorithm would result in an integer "rounded" value of 10.
Again, this is conjecture on my part, but it may provide an explanation.