Paypal and Membership problems?

Hello, firstly I’m in Britain and my website focus is on the US market. However I have received payments in $ before and do have my paypal account setup to accept US dollars which is shown under my balance screen on my paypal account. When a user on my site tries to purchase a membership package it takes them to an error page saying this “This recipient does not accept payments denominated in US. Please contact the seller and ask him to update his Payment Receiving Preferences to accept this currency.” I cannot understand why?

Also I have 3 membership packages, free, standard, premium. Free is obviously displaying a cost of 0 while the others show figures such as 60$ for premium though when I sign up as a user to test it and select free I cannot access anything as it tries to charge me 60$ and cannot understand why?!

Thank you for all your support.
Many Thanks,
harry.