integration in CAS

[Snorre]

Simplifying that unresolved integral two times raises another question:
Why does it give complex results (a decomposition of Si(1/√x) to its real and its imaginary part) even if CAS setting "Complex" was unchecked?
   
Worse: if "Complex" is checked, it outputs an endless repetition of "Error: Invalid series expansion: non tractable function im at +infinity" (sometimes reboots).