Keyword local completion doesn't work with loaded buffers in Vim

When I want to autocomplete with CTRL-N from other buffers, vim doesnt find any matches. I have no idea how to find out what's the problem. My complete settings are the default: complete=.,w,b,u,t,i. It only works for the active buffer. I even tried to :set complete+=U开发者_JS百科 but no success... How could I track this down ? My vim version is MacVim (7.3, snapshot 61).

Seems like Supertab plugin was responsible for the annoyance. (See the comments above)

In my case it was sparkup ftplugin.

Had to add let g:sparkupNextMapping = '<c-g>n' (or whatever key you like) to my .vimrc before I load the bundle.