First of all, let me mention that one crash per hour is pretty much ok for Synfig. So I don’t see much reasons to treat your case as “more unstable than usual”.
Analysis of core file sent by you doesn’t gives me anything valuable. Without any additional information (i.e. steps to reproduce the problem) I cannot help you. Please try to track your activity and find the pattern triggering the crash, then report it to the bugtracker.
There is only one thing I can advice in such conditions: try to close the Navigator Panel - it might heavily increase the program stability.