0.01 and 0.00999... represent the same real number.
SAS does not store decimal numbers exactly (unlike, say, COBOL). It stores all numbers as real numbers. A base-10 decimal number cannot be represented exactly in a base-2 system (integers can be represented exactly).
There are also a couple of standards for the internal structure of a real number. There is possibility that DB/2 and SAS use different standards, which could exacerbate this problem.
To really tease it out you will have to read the "fine print" in both DB/2 and SAS for numeric representation.