The digest entry of qt-x11-opensource-src-4.1.2.tar.gz is broken. http://www.gentoo.org/cgi-bin/viewcvs.cgi/x11-libs/qt/files/digest-qt-4.1.2?hideattic=1&rev=1.3&view=markup says correctly the file is 27MB big. All later commits truncate it to 11.5MB, 2.5MB and the last one to 9.7MB. The file I fetched from the gentoo-mirror has the size and md5sum from CVS revision 1.3
Should be fixed. http://sources.gentoo.org/viewcvs.py/gentoo-x86/x11-libs/qt/files/digest-qt-4.1.2?rev=1.7&view=log