Garry
Can you explain why for example, if 1 person lives in Bristol and another person lives in Exeter and they both type into google "carpet cleaners Birmingham" why do they see different page results? because surely were they live should have no effect on the search results for Birmingham?
Alan
The honest answer is "no, I cannot"

That is what happened when Gary and I looked at the Weymouth results.
There are different data centres around the world and sometimes you can get a difference in results depending on where they pull the data from at various times. I'm surprised that places as close as Exeter and Bristol yield different ones, especially when using a geographical modifier such as "Birmingham".
There is also Geotargeting, where if someone types in a generic keyword like say, "carpet cleaning" (without the town name), they should get served up local results according to their IP address.
As I said above, there have been two big Google updates recently and many people (myself included) have taken hits. To rub salt into the wounds, a competitor who is building a network of spammy backlinks and satellite mini site network with lousy content has actually gone up! So much for rewarding original content.... c'est la vie.