Why does this simple std::thread example not work?

Tried the following example compiled with g++ -std=gnu++0x t1.cpp and g++ -std=c++0x t1.cpp but both of these result in the example aborting.

$ ./a.out 
terminate called after throwing an instance of 'std::system_error'
  what():  
Aborted

Here is the sample:

#include <thread>
#include <iostream>

void doSomeWork( void )
{
    std::cout << "hello from thread..." << std::endl;
    return;
}

int main( int argc, char *argv[] )
{
    std::thread t( doSomeWork );
    t.join();
    return 0;
}

I'm trying this on Ubuntu 11.04:

$ g++ --version
g++ (Ubuntu/Linaro 4.5.2-8ubuntu4) 4.5.2

Anyone knows what I've missed?