webzilla - 7:58 pm on Oct 7, 2004 (gmt 0)

I have several sites hosted on a server which is physically based in the UK (I am in US, and catering to US traffic).

Several months ago traffic/rankings on google for these sites tanked, but they continue do rank very well for their targetted terms on google.co.uk when "Pages from the UK" button is checked.

These sites have reasonable PR, and there is no crosslinking, bad neighborhood linking or any other common no-no's.

Should I assume that the physical location of the server is the problem, or could there be some penalty/filtering factors that may apply more strongly on US than on UK searches?