Below are a couple error messages I received after running the Trivial Drive demo and how I fixed the issues. The first one is the most similar to your issue but keep reading because part of the second may apply to you too.
Problem: Screen message displays "One Second" for a long time then eventually shows an alert dialog, "Error:Failed to query inventory:IabResult:Error refreshing inventory...", then the message goes back to "One Second" and stays stuck on that message (like you describe).
Solution: Go to Settings->Accounts&Sync and make sure "Background Data" is checked.
Problem: You fix the issue above, link over to Google Play but receive this message, "The version of the application is not configured for billing through Google Play."
Solution: You can run the app with your debug key, but you won't be able to successfully purchase anything on Google Play if you don't export the apk with your production key. So instead of the "easy way" of running the app from Eclipse, you need to File->Export-> and go through the process of creating a production apk with your production key's password, etc (just like deploying a real app). I then go to a DOS command and "adb install MainActivity.apk" to install it on my phone.
The Trivial Drive "readme" file is very good: start there and make sure you follow every step explicitly. You will have to upload the production apk, THEN setup the in-app products, wait a few hours for Google to process things, then you will be able to test. It is a back-and-forth process since there is no staging environment.