"I have almost 600 hours in on this WU, with another 180 to go (about). I've heard of a lot of problems with upgrading to a newer version of CP mid-way thru a WU, so I'm going to wait until this run is complete before getting the next version."
I've recently upgraded three systems (XP Home, XP Pro & Windows 2000) to 4.13, mid-run with no problems. Simply suspend and exit BOINC, install the upgrade and restart. BOINC will report the software upgrade, run the benchmarks and restart.