MHes - 1:37 pm on Mar 11, 2007 (gmt 0)

With a .co.uk you should have no problems wherever you host. There was talk about Google recently having corrupt data for their 'ip location look up' but this should not be an issue for you, as you have a .co.uk domain. We have the same and are hosted in US with no problems.

Changing hosting to a UK server would stop you having any further doubt, but my gut feeling is that you have a different problem. At first glance, your symptoms sound like the 950+ penalty, where site pages bounce from being top to bottom, sometimes in 3 or 4 day cycles, for some popular search phrases. There is a thread about this, so see if this fits your observations.