C++ Program Always Crashes While doing a std::string assign

I have been trying to debug a crash in my application that crashes (i.e. asserts a * glibc detected * free(): invalid pointer: 0x000000000070f0c0 ***) while I'm trying to do a simple assign to a string. Note that I'm compiling on a linux system with gcc 4.2.4 with an optimization level set to -O2. With -O0 the application no longer crashes.

E.g.

std::string abc;

abc = "testString";

but if I changed the code as follows it no longer crashes

std::string abc("testString");

So again I scratched my head! But the interesting pattern was that the crash moved later on in the application, AGAIN at another string. I found it weird that the application was continuously crashing on a string assign. A typical crash backtrace would look as follows:

#0  0x00007f2c2663bfb5 in raise () from /lib64/libc.so.6
(gdb) bt
#0  0x00007f2c2663bfb5 in raise () from /lib64/libc.so.6
#1  0x00007f2c2663dbc3 in abort () from /lib64/libc.so.6
#2  0x00000000004d8cb7 in people_streamingserver_sighandler (signum=6) at src/peoplestreamingserver.cpp:487
#3  <signal handler called>
#4  0x00007f2c2663bfb5 in raise () from /lib64/libc.so.6
#5  0x00007f2c2663dbc3 in abort () from /lib64/libc.so.6
#6  0x00007f2c26680ce0 in ?? () from /lib64/libc.so.6
#7  0x00007f2c270ca7a0 in std::string::assign (this=0x7f2c21bc8d20, __str=<value optimized out>)
    at /home/bbazso/ThirdParty/sources/gcc-4.2.4/x86_64-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h:238
#8  0x00007f2c21bd874a in PEOPLESProtocol::GetStreamName (this=<value optimized out>,
    pRawPath=0x2342fd8 "rtmp://127.0.0.1/mp4:pop.mp4", lStreamName=@0x7f2c21bc8d20)
    at /opt/trx-HEAD/gcc/4.2.4/lib/gcc/x86_64-pc-linux-gnu/4.2.4/../../../../include/c++/4.2.4/bits/basic_string.h:491
#9  0x00007f2c21bd9daa in PEOPLESProtocol::SignalProtocolCreated (pProtocol=0x233a4e0, customParameters=@0x7f2c21bc8d