"might be used uninitialized..." what?

It's possible that I'm blind on both eyes.

After all, it's late in the day (or morning) for me.

But, I have this code which adds a string to a list of strings:

     virtual cppx::Index add(
         cppx::WideString const& s, cppx::WideString const& data
         )
     {
         int const id = myStrings.add( data );

         try
         {
             return Base::basicAdd( s, id );
         }
         catch( ... )
         {
             myStrings.remove( id );
             throw;
         }
     }

Compiling with g++ 3.4.5, options (copy/paste from the IDE's build log)

   -Wall -O -pedantic -Wall -g -O -pedantic -Wall -std=c++98 -Wno-long-long
-Wwrite-strings

the compiler complains that

     warning: 'id' might be used uninitialized in this function

Now, I've tried to *reproduce* the warning, with the following code:

     int add(); // { return 666; }
     void remove( int ); // {}
     int foo( int ); // {}

     struct S
     {
         virtual int bar()
         {
             int const id = add();
             try
             {
                 return foo( id );
             }
             catch( ... )
             {
                 remove( id );
                 throw;
             }
         }
     };

     int main()
     {
         S().bar();
     }

But this code does not produce the warning.

What is it that the compiler sees that I don't see?

Cheers & TIA.,

- Alf