Another segfault, this time not a random one, occurs with 0.3.1, immediately after starting the game in creative mode.
More info (output from the program, backtrace from gdb and content of debug.txt) is available here:
http://chkw386.ch.pwr.wroc.pl/~strasbur/minetest.err .
Note the following message:
INFO: Initial run of init_mapnode with g_texturesource=NULL. If this segfaults, there is a bug with something not checking for the NULL value.
I hope it helps. BTW, 0.2 works OK with exactly the same settings.