Hi Tony,
I just upgraded from 6.2.3 to 6.3.1 and spent about 30 minutes to find out the darn '\' problem. I figureed it out that's because the editor at admin page so I edited the related file with other editor.
Then I saw your thread, hope I saw this thread early. <img border="0" title="" alt="[Smile]" src="images/icons/smile.gif" />

CookyChen