After some time has passed, I just wanted to give some final feedback. I basically followed the suggestion by Alejandro and placed the same symbolic links appearing in the maple lib directory also in the directory where I run my programm. This worked, even though I do not fully understand why this is. 

Anyway, I want to thank anyone in here for their help and suggestions.

mank

@Alejandro Jakubi 

Hi,

when I execute the integrals (the simple example and the real ones) in maple itself, the correct results are given.

Best,

mank