Microsoft said Friday that it has updated its handheld synchronization software to address a glitch that had affected some customers. The software maker said ActiveSync 4.1 should fix problems that some buyers of new handhelds encountered when trying to share information with a PC. The issue affected devices that were running Microsoft’s Windows Mobile 5 operating system and that tried to connect to a computer over a USB connection, particularly when a firewall or parental control software was in use.