Goggle account sync fails

I noticed that items I added to Google Calendar have not appearing in iCal. So, yesterday I logged in to Plaxo, looked at my Google sync point, and clicked the link to sync immediately. That failed. I tried again today, and it failed again.

I then tried deleting the Google sync point and re-adding it. When I type in my username (both with and without "@gmail.com") and password and click "Next," I get the message "We're having trouble synchronizing with your Google account" and cannot continue.

I verified that I am using the correct password by logging out of Gmail and logging back in with that password.

I'd really like to get Google sync working again — is there anything I can do?