I use LWP::UserAgent version 2.036 from distribution libwww-perl-5.808. The method progress was added since libwww-perl-5.806. Upgrade your version and try again. I wonder however my code runs at all with libwww-perl-5.805 (that included LWP::UA 2.033 which didn't provide method progress yet).

Update: How stupid of me. My code runs with LWP::UA 2.033 because the method progress isn't called at all