prefer \setisabellecontext;

--- a/src/HOL/document/root.tex	Sun Nov 02 18:16:19 2014 +0100
+++ b/src/HOL/document/root.tex	Sun Nov 02 18:21:14 2014 +0100
@@ -25,8 +25,7 @@
 
 \newpage
 
-\renewcommand{\isamarkupheader}[1]%
-{\section{\isabellecontext: #1}\markright{THEORY~``\isabellecontext''}}
+\renewcommand{\setisabellecontext}[1]{\markright{THEORY~``#1''}}
 
 \parindent 0pt\parskip 0.5ex
 \input{session}