Question: accuracy of calculation in do loop.

Hello,

I want to calculate the IDs product :

Where gD:= 2: uS:=46.55077721:uB:=50.44144932:wiD:=-61.04353077:

Result of seperate calculation: 1.945311700e22
Result calculationin loop: 1.945311702e22

The problem is that Maple delivers different values of the IDs product when i do the calculation in a do loop for different vales of uS, while IDs is correctly calculated when the calculation is performed seperatly (not in do loop).
The difference is small but causes big problems to my programm.

I suppose the problem is due to the different approximations of the results in the do loop and the separate calculation.
I also tried by given Digits:=50: but then the do loop delivered again differnt value of IDs than the separate calculation.
(in that case IDs:= )

Can anybody give me a hint how i can contlol the accuracy of the calculations or/and  what is different between the calculation conducted in a do loop and seperately.

Thanx in advance,

Thanos Universität Erlangen-Nürnberg