Several of us have experienced repeated failure when uploading zip files. It turns out that we are all using AVG as our anti-virus product and this is causing the problem. We have raised it with AVG and they say it will be fixed <quote> in the next few days </quote>
In the mean time, the AVG forums have a work-around which other AVG users say has worked for them, though as far as I can see none of them is a CPDN cruncher.
Their work-around is to disable the AVG LinkScanner and/or disable the AVG Active Surf-Shield within AVG LinkScanner.
The other workaround which has been employed successfully by myself and other CPDN crunchers is to reboot the PC in \"Safe Mode with Networking\". To do this, press the F8 button during Windows boot-up and select the appropriate option from the list offered. BOINC can then be started and will upload the zip files successfully. When complete, the PC can then be rebooted normally.
All a bit clunky, but hopefully the workaround will not be needed much longer.