js injection - dynamically delivered by host

my html files have no problems , no injections. yet im getting the exact same problem as reported here - .js code at bottom of some sites on same server. its not all sites but enough. same code too.

http://www.vps.net/forum/public-forums/technical-discussions/3236-js-injection-throughout-server

anyone experienced same. and how can i guide host as to where to look for teh problem. seems it comes and goes daily..

google now blocking sites.

no file dates recently changed which is why i believe this is being dynamicaly delivered. very little in google about this.. usually it affects files on the server.