When using .. include:: somefile, and somefile has an error, the error is reported to be in the original file in an inexistent line (as if the files would be merged together). It's really hard to find errors this way =/
Fixed; thanks for the bug report.
You can download a current snapshot from:
Reopening, as the fix is only partial. See also `Docutils Bugs` (http://docutils.sourceforge.net/BUGS.html).