I'm going to take a stab in the dark and suggest that your configuration is probably resulting in no highlighting.
You can check this with the command :verbose highlight SpellBad: if the xxx at the start of the line is not highlighted, then badly spelled words won't be highlighted, either.
You can fix this by setting the highlighting yourself. You can simply add :highlight commands to your vimrc, but a better way is probably to use a ColorScheme autocommand. e.g.:
augroup my_colours
autocmd!
autocmd ColorScheme adrian hi SpellBad cterm=reverse
augroup END
Put this before the colorscheme line in your vimrc.
See :help :highlight and :help ColorScheme for more details.