simonuk - 2:59 pm on Feb 2, 2009 (gmt 0)

I haven't had a co.uk site on a USA server for about 4 years so I might be out of date on this paragraph but I know my other co.uk's and .coms on UK servers did rank better for me for searching with the UK. It didn’t matter if I was on googles .com or co.uk they both returned better for my sites on UK servers.

My .com's on UK servers always rank better for UK searches whether that be the Googles .com or .co.uk site (It is currently ranked 6th out of 170 million sites for the biggest searched word and the plural version one as well).

I have not tested USA sites on USA server and USA searching but UK searches for UK sites on UK servers has always been higher up the list.

You say your products are growing steadily? Is it a gradual few a week or months of nothing and then a bulk going on? Slow and steady is always better than sudden big surges.

I used to test on another version of the domain like you but I never linked to the main site in case the test site got penalised and that rubbed off on the main site. This sounds like it might be a reason to me (especially if you mirror even a small amount and that mirroring is picked up).

Finally you admit there were some footer linking issues that may have caused it. Fixed those first and go from there.