to reproduce: run mirrorselect with xdialog, select a few servers, hit ok... note lack of spaces before each ftp:// and http:// which does not jive well with portage. Star root # mirrorselect -i -o Downloading a list of mirrors... VHOST entries have been removed. This list might be shorter than expected GENTOO_MIRRORS="http://adelie.polymtl.ca//ftp://cs.ubishops.ca/pub/gentoo/ftp://sunsite.ualberta.ca/pub/unix/Linux/gentoo/"
this has now been fixed in 0.83 and should be in portage stable quite shortly. not sure why xdialog has started to do this, but as a precaution i now sed out the MIRRORS to ensure it is futureproof