The manifest contains "DIST gtkpbbuttons-0.6.10.tar.gz 714229" but the file download from the project's home page is 713779 bytes. I have tried removing the file from $DISTDIR and letting portage download again, as well as downloading directly and always get a 713779 byte file
Well, that's strange. I've re-uploaded the gtkpbbuttons source to our mirrors and fixed the digest. Thanks for noticing and letting me know!