When I want to check a word with the British dictionary (ispell -d british), the program accepts both British and American spellings. For instance both traveling and travelling are marked as OK. The problem seems to be related to the /usr/share/dict/words file. I removed the /usr/share/dict/words, created an empty one and re-emerged ispell. This time the British dictionary accepted only British spellings.
miscfiles-1.3-r2 no longer installs the words symlink, just the words.extra symlink.
This bug should be reopened since removing /usr/share/dict/words broke stuff (like the compilation of ispell...) and the file is now present again (miscfiles-1.3-r1 is now the default again). I haven't studied this closely, but i think a fix really should include removing /usr/share/dict/words from the EXTRADICTS options to amarican and british in local.h in ispell-3.2.06-gentoo.diff.
finally fixed this for real