Synchronisation problems with bookmarks with Safari 3.1

Many people have met the problem of synchronisation of their bookmarks after the Safari 3.1 update in Mac OSX 10.5.2.
This syncing problem affects iPhone, Ipod Touch and the .mac accounts.
Apple has published a solution:
- Quit Safari 3.1.
- Open Terminal (in /Applications/Utilities).
- Type or paste the following command in Terminal:
defaults delete com.apple.safari RegisteredSafariSyncClient
-Open Safari 3.1 again.
-Sync via .Mac again.