Still? It may have been related to the fail reports that were spawned in multiple threads and taken up by the techs in the Known Issues form: http://www.worldcommunitygrid.org/forums/wcg/viewthread_thread,29271. Took my client from around 00:24AM when the log showed connection fails till about 4:19 AM CET when the client managed to get through (whilst I was asleep)

Thu 01 Jul 2010 01:38:43 CEST Project communication failed: attempting access to reference site
Thu 01 Jul 2010 01:38:43 CEST World Community Grid Temporarily failed upload of E200014_239_A.15.C11H8N2SSi.77.set1d06_1_4: connect() failed
Thu 01 Jul 2010 01:38:43 CEST World Community Grid Backing off 1 min 0 sec on upload of E200014_239_A.15.C11H8N2SSi.77.set1d06_1_4
Thu 01 Jul 2010 01:38:47 CEST Internet access OK - project servers may be temporarily down.
Thu 01 Jul 2010 04:14:01 CEST World Community Grid Started upload of E200014_212_A.15.C11H8N2SSi.52.set1d06_1_4
Thu 01 Jul 2010 04:18:58 CEST World Community Grid Finished upload of E200014_212_A.15.C11H8N2SSi.52.set1d06_1_4
Thu 01 Jul 2010 04:18:58 CEST World Community Grid Reporting 1 completed tasks, not requesting new tasks
Thu 01 Jul 2010 04:19:09 CEST World Community Grid [sched_op_debug] handle_scheduler_reply(): got ack for result E200014_212_A.15.C11H8N2SSi.52.set1d06_1


PS: I've asked admin to move this thread to BOINC support.