For people experiencing errors with optimised apps and ubuntu 9.04, switch your kernel to intrepid's (8.10) one, currently 2.6.27-14. I've been running with this config for a week with absolutely no problem or error in seti. Previously, with jaunty's kernels (both 2.6.28-11 and 2.6.28-12) I was getting at least 2-3 errors a day with astropulse sse3 64bit.
So the error lies with ubuntu's version of the 2.6.28 kernel itself or some combination with other files.
If you absolutely need a 2.6.28 kernel, because of ext4 or some specific driver, you can try compiling your own kernel from vanilla and why not, If you take this route, go with newer kernel (2.6.29 or 2.6.30rc). Vanilla versions probably will not exhibit these problems we're experiencing with jaunty's kernel (after all, there aren't any reports with errors in other distributions).
You could also try
this. It is a repository of mainline kernels neatly debian-packaged by ubuntu's kernel team.
