Can somebody explain why I am third for a keyterm on google.com and 5th for the same term on google.co.uk (when searching the web not just .co.uk) I understand that if it was UK only pages there would be a difference but searching the web? Shouldn't that be the same as .com? Also none of the sites seem to be from the UK so how did this happen?
google.com and google.co.uk has their data center. when you search from google.co.uk then would show most of Uk's IP address's result only. then else.
Inspite of having different data centers, they do have pages from rest of the world. My Site is visible from all Google engines from UK, brazil, USA, newzealand and more.... so Above comment that country spefic google only crawls country IPs is wrong. It priotize Uk spefic searches on Uk engine.
This is just data center issues, remember the data centers all contain different data in different geographical locations. Even when you search on *.co.uk and use the entire web it will still favor results towards the UK area but will not be as strict as only in the UK results.