http://screenr.com/fsl 0:00–0:06 Everything works well. 0:06–0:15 "xml-stylesheet" displayed instead of DOM tree. 0:17–0:22 Works well again
Created attachment 70110 [details] Reduction
Sounds like Reload with front-end opened makes front-end unhappy. Thanks for reporting.
Created attachment 70111 [details] XSLT