sending Stl containers to dll - c++

Question

Before going to the question, kindly understand my project environment.
I have a class in my DLL, which contains nested stl containers and structures as members.
By using the DLL class header files, my application is dynamically allocating memory to the dll's class object and sending it to the dll, to fill data by reading files.
Now, at tool side, I am able to get the data of structures in the class, but unable to get the data of stl container.
-> What is the reason behind this ? Is passing stl containers to dll is OK ?
Note :
Both DLL and application is compiled using same code studio. Both are in 32 bit.
I have tried to send the container by reference and by object too. Both are not working.
The same code worked properly when I created a demo application before shifting the required code to the dll.
One more point.., When I debug the library, I can see that data is getting filled in the container, but when I comes back to the application, no data is present. One interesting fact in debugging is, Let us say I stored 3 objects in my stl containers, on debugging , when control comes back to application, I am able to see the count when I watch the variable.
It is something like "comp | less" and remaining tags are "error".
Please consider the below code :
bool CMyClass::ReadHeaderData(
) {
bool status = false;
CMyLib *lib_obj = ((CMyClassApp*)::AfxGetApp())->GetLibObj ();
for (int cnt = 0; cnt < 5; ++cnt) {
CString file_path = GetFilePathOfHeader(cnt);
if (PathFileExists(file_path)) {
CMyEntity* entity_obj = new CMyEntity;
if (lib_obj ->FillHeaderData(file_path, entity_obj)) {
//some processing
status = true;
}
}
}
return status;
}
Sample Entity class structure is :
CMyEntity {
struct1 {...};
struct2 {...};
std::map<key1, std::map<key2,value> >;
};
** When I try to send the pointer reference of stl container directly to the DLL, it is working fine. The only problem is when I am trying to send it inside my class object.
If the stack frames for DLL and application are different, why the data is coming inside structures ? why it is not coming only for stl containers ?