boost::shared_ptr error at end of class

class SomeData{};
typedef boost::shared_ptr<SomeData> data_ptr;

class ABC {
public:   ABC(){}

          ~ABC(){cached_ptr.reset(); }

          data_ptr get_ptr() {data_ptr x; return x;} // it does work and returns a data_ptr

          bool someWork(data_ptr& passed_ptr) {
            if(cached_ptr == NULL) {
              cached_ptr = get_ptr();
              passed_ptr.reset(new SomeData(*cached_ptr));
            }
            return true;
          }

          data_ptr otherWork() {
            if(cached_ptr == NULL) { 
                cached_ptr = get_ptr();
                data_ptr local_ptr = boost::make_shared<SomeData>(*cached_ptr);
            }
            return data_ptr;   // after some more work
         }

private:  data_ptr cached_ptr;   // class member
};

The above is a simplification of some code that I am trying to get to work.

It did, until I added the "cached_ptr", the ability to cache data between successive calls to avoid calling get_ptr() every single time (it can be fairly big).

Note: I have boost::make_shared and reset() - I experimented with both to see if the error was caused by the copy. It didn't make a difference (As expected).

I already have google test unit tests in place - and when I added the cached_ptr, google test has been giving me errors of the "GTEST_HAS_SEH" kind.

"unknown file: error: SEH exception with code 0xc000005 thrown in the test body."

The error occurs on the destructor: cached_ptr.reset();

Visual Studio says:

    "First-chance exception at 0x00ceba41 in myFile_gtest.exe: 0xC0000005: 
Access violation reading location 0xfeeefeee."

It occurs without it as well (initially I didn't even place a reset(), I thought that a shared pointer kills itself when it runs out of scope.

What could be my problem ?

boost 1.47

Thank you.