HOWTO fix shared Google calendars not showing up in Android

Google calendar is a simple and useful tool for sharing informations about events and tasks with colleagues. The nice part is that you can gather many calendars and sum them up in a single view. The even nicest part is that everything flows into your android mobile, so you can have a collaborative real-time calendar in your phone.

So, what's the matter? Well, the web-based calendar runs perfectly, but sometimes Android messes up: some calendars, which are correctly shown in Google Calendar, do not appear in Android. Repeating the synchronization does not fix a thing, you have to get dirtier than this.

Go to Settings > Applications > Manage Applications > Running > Calendar storage

Then, click "Clear data" and "Force stop". The first one wipes out the local cache; the latter forces the calendar to restart and download the calendars again from the internet.

A bit messy, but it works.