That explains why the workflow still works for me - the GMapstoGPX javascript snippet is just a bookmark in my browser, and when I use it, the xml code that is generated has
<gpx version="1.1" creator="GMapToGPX 6.4c
as part of the header.
As wothill supposed, the update is automatic at their end - or it was for me anyway. I've used the utility a few times over the past 2 weeks and not noticed any problems. Or maybe I'm just so used to a few stumbles (because Mapsource is very intolerant) and just pass the .gpx through EasyGPS or GPSBabel without even thinking about it - both of these utilities are very good at cleaning dodgy code.