The -domain part of a cookie should be the domain name of the server(s) that you want to receive the cookie (1). 'B2R6A056a' does not look like a valid domain name to me, and that is probably causing your problem.
My suggestion would be to simplify things by removing the -expires and -domain part of the cookie, and seeing if that works. If it does work, then add one of the options back in ans see if things still work. Simplifying things and taking it one step at a time is a very successful debugging tool that is useful when you are not sure what is causing your problems.
If that doesn't work, then you need to start looking carefully at the actual headers being sent along with the request (that includes client headers and server headers). Mozilla can be helpful with this, since it has plugins to debug client and server HTTP headers. Look for the Set-Cookie: header in the server headers, and Cookie: header in the client headers.