Last week, I did a hardware upgrade on my home PC. Originally, I had an EliteGroup 848P-A motherboard with a Pentium 4 2.8GHz (Prescott) with 2 GB of DDR 400 RAM. The new configuration has a Gigabyte GA-P35-S3G motherboard with a Pentium Dual Core E2220 (2.4GHz) and 4 GB of DDR2 800 RAM. It was a pretty cheap upgrade, and performance on compute-intensive tasks seems to be about 2x faster. Kubuntu 8.04 recognized all of the new hardware; no reconfiguration was necessary.
Weirdly, there is one important application that no longer works following the upgrade: Eclipse. I get repeated segfaults in libjvm.so. As far as I can tell, it's not a hardware problem. All other applications I have tried have been 100% stable, my CPU temperature has not exceeded 41 C for either core, memtest86+ did not find any problems with the memory, etc.
So, I conclude that it's some sort of software problem. Could it be a weird interaction between SWT and gtk+? This is where native code really sucks.
In the meantime, I'm using Netbeans for Java development. It's gotten quite a bit better since the last time I used it. It's maybe not quite as polished as Eclipse, but the important features (code completion, cross-referencing, and refactoring) are there.