Your pattern is correct. Your code is largely correct with few missing 'std'' here and there (for 'cout', 'endl' and regex_match), or at least inconsistent (assuming you are 'using namespace std').
Moreover, on Visual Studio 2012, your code output the expected result. I didn't try 2010, but I suspect it is running there as well (Microsoft incorporated TR1 back in 2010).
I suspect you are using gcc. As @Artyom pointed out, in gcc/libstdc++ isn't implemented. It compiles fine with no warnings but it gives the wrong results. Despite the common belief that gcc is superior than Microsoft in every area, this isn't the case in regular expression.
Find status of regex on gcc here:
http://gcc.gnu.org/onlinedocs/libstdc++/manual/status.html#status.iso.200x
