After upgrading my Boinc from v4.05 to v4.09, Climate Prediction seems to lock up my computer. When I kill the processes running the software, my computer unlocks. I believe there might be a compatibility issue w/ the 2 versions.

By any chance do you have a dual processor or HT machine? There is an existing problem with BOINC GUI 4.09 and multi-processor machines when there is not enough work for both processors.

I myself am locked out today after having lost 220 hours of work on one CPDN WU, and erroring out of about 3 more new WU's in an attempt to fix it. Apparently the fix (until a new BOINC GUI comes out) is to set your GENERAL prefs to use only 1 processor. This may or may not work, since upon rebooting or restarting BOINC, it hangs right away, before you can attempt to update.

If you kill the BOINC GUI process, then the two HADSM processes (in that order), no harm is done to the WU's (however, the problem remains, and when you start up BOINC again it will hang). If you kill the HADSM processes first, the BOINC GUI will dump them claiming a processing error. If you have a lot of time invested in a WU, you will lose it. However, this seems to be the only way to get the client to attempt an update.