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).

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

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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.