Eu tive um problema semelhante e resolvi-o com o conselho de suporte do Google. No meu caso, havia duas impressoras com o mesmo nome e isso causou um problema. Além disso, você não nota qual sistema operacional está usando, mas há um requisito para que o Windows XP tenha o sp 3. Também estou usando o Google Chrome, conforme sugerido pelo Google.
Suas sugestões:
Make sure your Google Cloud Print connector is running on a computer that is turned on and using the latest version of Google Chrome.
Make sure your printer is on and connected to the computer running the Google Cloud Print connector.
Make sure you're printing to the correct printer. Sometimes, there may be duplicate printers shown.
In Google Chrome, select Settings and click the Show advanced settings link. In the "Google Cloud Print" section, click Sign out of Google Cloud Print. Visit the Google Cloud Print management page and click on Printers. Delete any duplicate printers (printers with the exact same name) and then sign in to Google Cloud Print again.