Just to make it more clear.
Inside the file uulib.c (cames in the ISPConfig 2.2.0 tar file) that generates such compile error there is only one include statement that calls io.h.
/* to get open() in Windows */
I am installing in Linux, how the hell did they spoof me
It seems that the compile does not make ./configure before starting compilation ...
Any one knows how to make this error go?