I shutdown my pc every night, and I used to lose the portion completed by tasks that had no chance to checkpoint before I shutdown.
I wrote a simple windows powershell script that shuts down boinc only after all tasks have checkpointed.
If you have a better solution to the problem above, or if you want to test the script, you can find it here:
http://gallery.technet.microsoft.com/sc ... r-6de3f2ae
Thanks
Amir