I have a problem in that I use a spreadsheet which uses automatic calculation. When I open the spreadsheet it calculates automatically but every now and again it switches the calculation to manual whilst I have the spreadsheet open... I haven't opened any other spreadsheets in this time so it can't be linked to the startup state of a particular spreadsheet or to excel itself. If I turn the automatic calculation back on using tools/options it starts working again...

Can anyone help. It's really doing my head in and is causing me some problems...

Thanks