Thanks amoore,
I use Acrobat 8 to generate pdfs but have Acrobat Reader 9 installed as the default reader. Acrobat 8 has an option to 'return to the last used page' but it is not checked; I don't believe Acrobat 8 is used by the browsers anyway. I am not sure what the browsers are using other than it is a version of Acrobat but none of my browsers (IE8, Chrome, Safari or Firefox) appear to give me the option to change this setting.

Grateful for any other suggestions but I can probably live with this if necessary.

Thanks again,
Trev