I have just moved www.victorianlondon.org to a new host.
I 'upgraded' my website to a new package on www.easily.co.uk and found that the advertisements/banners did not work anymore.
Easily were, frankly, rubbish in dealing with this. I waited days and days. There were two long phone calls explaining the problem; several emails and - in the end - my own research (and I am an ignoramus on programming and servers) narrowed it down to a likely cause. I won't go into the technical details but the 'solution' eventually proposed was basically to rename all the files extensions on my site. Several thousand of them. Files which had worked perfectly well on their old setup. Files to which lots of people already had links, links which would then be broken. Files which, incidentally, now work fine, migrated to the new host.
I will stop what could turn into a long whinge. The short summary www.easily.co.uk - best avoided, if you want anything remotely resembling support or customer service.