Calculating area graphically on the HP50g appears inaccurate

[cdecastro]

If I graph the function y=sin(x), find the root at x=0 using FCN->ROOT, set the mark (via "X"), find the zero at Pi again using the root function, then request the AREA, I get the answer 1.99913515027 rather than 2. I am assuming the calculator is not really moving the end mark to Pi but rather to the x value of the nearest approximating pixel (with respect to the scaling in the current plot window). Is this correct? If so, graphically computing areas should not to be considered as accurate as the evaluation of the corresponding definite integral. Thanks in advance for your assistance.

Appreciatively,
Chris