I found the problem

The manual says:

Quote

Due to the 7 digit limit, var X = 123456789.0; would in fact set X to 123456792.0; but var X = 123456789; sets it to 123456789.0 since int has 10 significant digits.


So, I changed the code to:
Code
		double a1 = 56434;
		double a2 = 56506;
		printf("\n %.10e %.10e %.10e",a1,a2,(a1-a2)/a2);


Got the desired results:

Quote


returns compiling............ ok

5.6434000000e+004 5.6506000000e+004 -1.2742009698e-003



Thanks
David