Have problem with HashMap on Linux

[ShrewMouse]

Hi All,
When I use HashMap on Linux:

Poco::HashMap < long, long > hashMap;

hashMap.insert(pair < long, long >(1,5));

There is an error occur :
../poco-1.3.2-data/Foundation/include/Poco/Hash.h call of overloaded 'hash(long int&)' is ambiguous

But everything is ok when i use the key by Int type:

Poco::HashMap< int, long > hashMap;

hashMap.insert(pair < int, long >(1,5));

The reason I use long type here is i need a big HashMap enough for storing info that is bigger than int type

currenlty I use RedHat Linux 9 and Eclipse platform 3.4.1
Thanks for any help

[ShrewMouse]

I find that the sizeof (int) and the sizeof (long) in my machine is the same , so at this time I can use Poco::HashMap < unsigned int, long > hashMap for my demand...