Hi,
If I remember correctly, the US and UK have a reciprocal tax agreement which I believe means you don't have to pay tax to both countries unless you make more than $80,000. If you make less than $80,000, you only pay to whichever country you live in. At the moment £60,000 is $87,000, so you might have to pay tax on the extra $7,000. (Disclaimer: All of that is from my memory, so don't use it as a basis for financial planning!)
For example, I do a lot of work for an American company's London branch. They pay me in pounds, but the payments are sent out of their New York office into my US bank account. They take out UK taxes, and give me a W2 to reflect that. When tax time comes, my US accountant does whatever tax magic she does to show that I've already paid taxes to the UK, so I don't have to pay them again to the US.
You should check with a professional to make sure what's happening in your situation, but it sounds like your situation is similar.
[EDIT] Here's a link to the IRS page that explains, briefly, what the deal is:
http://www.irs.gov/faqs/faq/0,,id=199678,00.htmlgood luck,
Carl