# split posted variables into pairs

If you're gonna do that, why not drop LWP entirely and just use IO::Socket?

At the very least you should use CGI.pm for params, see Re^3: Get those parameters without CGI.pm as to why

Basically, whatever the problem with your program, chances are its because you're not using CGI.pm -- it probably has nothing to do with http 1.1 at all

yet another argument for using some paypal module