Missing spaces after EL expressions in JSP

Spaces are missing after EL expression in the output. For example the following
${x} ${y} ${z} comes out as "xyz" (assuming the values bound to the variables are "x", "y", "z", respectively) or ${x} text comes out as "xtext".

The behaviour is the same on WF 10 and 11. Does not occur on Tomcat 7,8.

The space is not present in the generated java class on WF and is present on Tomcat, so I assume the problem must be in the JSP parsing.

My only lead so far is this stackoverflow question back from '08.