Hi,

I am not sure but maybe it is a bug: in duplex documents empty lines
causing a mess with the margins on every second page. 

Following lines create a fine pdf documents and all margins are set
correctly in the pdf file:

...
\ininner{X X X X X X X X X X X X}\inouter{M M M M M M M M M M M
M }\input tufte
\ininner{X X X X X X X X X X X X}\inouter{M M M M M M M M M M M
M }\input tufte
\ininner{X X X X X X X X X X X X}\inouter{M M M M M M M M M M M
M }\input tufte
...

But as soon I add between every two lines an empty line the margin on
every second page are corrupted. I am using the context version
2011.11.08.

I attached example files to reproduce and show the problem:

	duplex-margin-with-empty-lines.tex > problem occurs

	duplex-margin-without-empty-lines.tex > no problem

Can anyone approve this problem? Or did I something totally stupid to
get this result? 

I attached a jpg that shows the problem.