N3230/iSync - works only first time, fails after putting iBook to sleep

When I wake it up iBook is no longer able to connect to N3230 unless I delete pairing and add N3230 again (and reinstall iSync Agent).
look^ wrote on :

I succesfully added, paired and authorised my N3230 device. Everything works fine (and I was even able to receive phonecalls and sens smses from Address Book) untill I put my iBook to sleep. When I wake it up iBook is no longer able to connect to N3230 unless I delete pairing and add N3230 again (and reinstall iSync Agent). Any help will be greatly appreciated.

thanks a lot, look^