Problems using std::queue() in Unix

I have the following code in my program:

std::queue<typename Leftist_node<Type> *> traversal;

It compiles and work fine when I run it on Windows. However, when I run the exact same program on Unix, I get the following error:

Leftist_heap.h:89: error: template argument 1 is invalid
Leftist_heap.h:89: error: template argument 2 is invalid

I also get these messages when trying to work with the queue:

Leftist_heap.h:92: error: request for member âpushâ in âtraversalâ, which is of non-class type âintâ

Is there any reason for this? Do I need to change something to make it work on Unix?