PAYE Tax Credits

Hi,

I recently switched from a sole trader to a PAYE worker. I got my tax credit certificate yesterday which states that I have a tax credit of 3,660 euro.
Now maybe I am missing something but that seems to be twice what I am entitled.
I am single so all I was expecting was 1,830 euro.
Any ideas?

plus PAYE credit of 1830

[broken link removed]
Income Tax rates and bands for 2008
Are you paying too much tax? A guide to tax credits
www.taxcalc.eu

Thanks for the replies and for the links.