Calendar access from apps: only some calendars are displayed
So I've finally solved it using the update command (disable sync; restart; update; restart; enable sync) and ot seems to work well. The update command was like:

UPDATE Calendars SET sync_events=1, selected=1 WHERE _id &gt; 3


I had tried compiling the Android Calendar from source, but I was getting sone errors about invalid NDK or SDK version.