When I'm writing tests and hit a snag within a module sub, I just use perl to run the test, which will allow you see the print statements within the module:

acct-dev: ISP-RADIUS % perl t/03-date.t
ok 1 - use ISP::RADIUS;
ok 2 - ISP::RADIUS->can('date')
ok 3 - date() dies if the get param is incorrect
...printing from module
ok 4 - calling date() with no params, return isa DateTime
...printing from module
ok 5 - called with get=>month works out ok
...printing from module
ok 6 - If the timezone isn't set correctly, we die
[download]

Hope this is what you were after

Steve