I studied the Response Headers for the ajax call that generates the output and found that for the correct result (ie. in TC55), the content type was this: Content-Type text/plain;charset=ISO-8859-1
while for the wrong result (ie. in TC6), the content type was: Content-Type text/plain So I added this line to my code : response.setCharacterEncoding("ISO-8859-15"); (I chose the ISO-..-15 set, to see if my change had effect) And lo and behold: problem solved ! So would this be the right conclusion : it's TC55 that's wrong here and not TC 6 ? TC55 slaps on the 'charset=ISO-8859-1' by default and TC 6 doesn't. Anyway, glad to have found the solution, thank you all for chipping in your ideas! Regards, Willem