The latest Parrot CVS checkout segfaults for me on the following code:
.sub _main .local pmc foo
foo = new Integer foo = 3
# new_pad 0 store_lex "foo", foo
end .end
It appears that the "store_lex" opcode is to blame - when no lexical pad has been created and you attempt to store a lexical, the SEGV is generated. Uncommenting the preceding "new_pad" line throws an exception as expected.
Cory