It looks like the problem is with your Picasa User Id and/or Picasa Album Name.
Check that the functionality is working OK by setting up a test gallery with the following information:
Picasa User Id: picasateam
Picasa Album Name: VegasWeekend
Please check your Picasa User Id. It may not be your email address.
Also, as Google have discontinued Picasa and are moving all Picasa web albums over to Google+ photo albums, you might need to enter Google credentials rather than Picasa ones.
You can find your Google User Id by logging in to Google+ and clicking the 'Google+ Profile' link above the 'My Account' button (after clicking your custom image at the top right). Your Google User Id will be the 21 digit number in the URL (in your browser's address bar).
Take a look at this forum thread which should hopefully point you in the right direction towards finding your Google Album Id (a 19 digit number).
I hope this helps.