just taking a look at the latest release, found a rather minor issue:
the itpp-4.0.0.tar.gz contains the files itpp.spec and itpp-config.1. however, ./configure regenerates these files, and make distclean removes them, so if you go through a standard "./configure; make; make distclean" cycle the source isn't left in the same state as it was previously.
one solution would be to not ship the files in the tarball, since configure makes them, but maybe you want the spec file in there since it can be used by rpmbuild to make rpms from your official tarball. i suppose another solution would be not to regenerate the files from ./configure?