This bug affected me as well on a fresh maverick install with the nVidia drivers installed.
I tried re-installing ubuntu, and I've managed to track down exactly what causes QT apps to crash - it appears to be to do with my multi-monitor setup. I have tried all X configurations (single, twinview and 'separate X screens', with and without xinerama) and it only occurs on separate X screens with xinerama enabled.
This bug affected me as well on a fresh maverick install with the nVidia drivers installed.
I tried re-installing ubuntu, and I've managed to track down exactly what causes QT apps to crash - it appears to be to do with my multi-monitor setup. I have tried all X configurations (single, twinview and 'separate X screens', with and without xinerama) and it only occurs on separate X screens with xinerama enabled.
Alejandro, are you using a multi-monitor setup?