google.com / .co.uk inconsistencies

UK site appears higher on .com results than on .co.uk with uk filtering?

[dawlish]

For about the past 6 weeks a particular website of mine has been appearing far lower in the search results of google.co.uk (with UK filter applied) than in either www.google.co.uk without the UK filter, or the www.google.com.

For example a search for keyword phrase lists my site in position 12 on www.google.com and position 31 on www.google.co.uk with the UK filter applied. This makes no sense at all? The same applies for every search undertake.

My site is a .co.uk and I have a one other site on the same server on a different subject and this has been unaffected and ranks higher on www.google.co.uk than on .com, as you would expect.

Has anyone else experienced this and does anyone have any insight as to why this maybe?