Could you please check after trying to start (and after synaptic has crashed) if there is anything in /var/crash? If there is a _usr_sbin_synaptic*****.crash file, please attach it here, for us to be able to investigate the issue, as I can't reproduce this locally using neither 11.10, nor 12.04 or 12.10.
Could you please check after trying to start (and after synaptic has crashed) if there is anything in /var/crash? If there is a _usr_sbin_ synaptic* ****.crash file, please attach it here, for us to be able to investigate the issue, as I can't reproduce this locally using neither 11.10, nor 12.04 or 12.10.