enums and unsigned ints in g++ 3.4.0 (x86_64)

[sridhar]

The following code gives unexpected results on an AMD64 machine 
g++ 3.4.0

enum Type {
 TypeA               = 0x01,
 TypeB               = 0x29
};

static const unsigned int TypeC = 0x20;

int main(void)
{

  Type  T =  TypeB;
  if(T & TypeC)
    printf("matches\n");
} 


The assembly code produced is
0:   55                      push   %rbp
   1:   48 89 e5                mov    %rsp,%rbp
   4:   48 83 ec 10             sub    $0x10,%rsp
   8:   c7 45 fc 20 00 00 00    movl   $0x20,0xfffffffffffffffc(%rbp)
   f:   83 7d fc 00             cmpl   $0x0,0xfffffffffffffffc(%rbp)
                // isn;t that strange,comparing with 0
'
  13:   79 0f                   jns    24 <main+0x24>
  15:   bf 00 00 00 00          mov    $0x0,%edi
  1a:   b8 00 00 00 00          mov    $0x0,%eax
  1f:   e8 00 00 00 00          callq  24 <main+0x24>
  24:   b8 00 00 00 00          mov    $0x0,%eax
  29:   c9                      leaveq
  2a:   c3                      retq 

On an x86 machine this works fine and prints 'matches' as expected.
I guess the enums in the above code would be signed ints.
If I change the condition to

  if(T & (int)TypeC)

it works. So what exactly is happening here?