SETI is refusing to download work units until I upgrade to the the new release of BOINC. I'm somewhat nervous about doing this because the last time I upgraded to a new version of BOINC it promptly got an error on my then-current climateprediction.net work unit, downloaded a new one and started over from scratch. I was at about 30% on that model and have just gotten back up to 30% on the new one. Has anyone successfully upgraded to the new BOINC (4.19, I think) without loosing their work to date on the ClimatePrediction model?

If one has a fundamental problem with one's computer, ANY new version could trigger a problem.
However, the latest, 4.25 from <a href="http://boinc.berkeley.edu/download.php"> here,</a> appears to be quite stable,
and makes use of the 'signed' feature in all models now being downloaded.

Backup the entire BOINC folder to another part of your HD first. Then, if anything goes wrong, you can just
move it all back.
Then download 4.25 into the BOINC folder, uninstall your current version, (4.25 INSISTS on this), run the new one,
and you're back in business.
Several of the old problems have been solved, and sooner or later everyone will need to move to the new version.
I've been running it for a week with no worries.

Les