PayPal Error 10004

[bekinky]

I have just installed the Paypal Express module and set up my paypal account to use the live express checkout. I have updated all the Paypal code in Zencart with the patch valid to 20th January. I checked the upload three times to be sure it went online and overwrote the files.

When not logged into Zencart, I buy a test product and got tp Paypal Express Checkout. It brings up a login box for me to login to my Paypal account. WTF? I am asuming it is because the cookie has been set by Paypal on my machine, so it recognises I have a Paypal account. Is this correct?

Second part of the problem: I login to zencart having created a test account then use Paypal Express. This time I get the following error message from Zencart:

An error occurred when we tried to contact the payment processor. Please try again, select an alternate payment method, or contact the store owner for assistance. (10004)

So what does that mean? How do I solve it? I read about posting log files but how do I get them and do they contain any sensitive data which should not be posted onto the forums?

By the way, this only happens if I go through normal checkout process. If I click the Paypal Express button at the start of checkout it goes to the Paypal site and asks for my login info.

Thanks for any advice