In my opinion this needs thorough investigation which will probably take a solid day if not several days to find out what is causing it. Everything is "suspect" from the configuration of the Server (it's own language, for example); the webserver engine and the configuration of that; the legacy plus advertiser's html code which must by agreement be added to each page (to pay for the site); any file corruption caused during the transfer from the old server ; etc. etc. And I may not even have mentioned where the cause of this problem is.
In order to investigate this properly it may even be necessary to bring the whole site offline. Alternatives are to spend lots of money duplicating the server and its setup. I have a feeling that money is not available.
In my opinion it is up to the people that pay for the site - the advertisers - to be pressured. I do not think that Torq however much of a genius he is has the power to solve this without that kind of intervention.
VV