.mac sync problem


After booting up and using my computer for a while, the first time I try to sync to my .mac account using the .mac preferences pane (in Tiger, 10.4.1), I get the following (erroneous) message at the END of the syncing process:

"This computer cannot sync to .Mac at this time. .Mac may be performing some maintenance or another machine of yours might be synchronizing. (Only one machine may synchronize with .Mac at a time.) Please try again later."

What is odd about this is that the preferences pane registers that a successful sync has just concluded, since it displays the present time as the "Last sync". Also, no such message is displayed if I immediately do another sync. Has anyone else noticed this bug, and if so, should we be concerned about it?