[Help-glpk] Memory allocation error

[at205]

I am writing a Java Gui which allows a user to run the model by pressing 
the "run" button and change some parameters. I have written my mode in 
MathProg and now I am using JNI for glpk. However I have a problem. After the 
user presses "run" a lot times (sometimes more than once) Java gives me this 
error:

ufree: ptr ..... memory allocation error

Do you think that it has to do with the solver?

My code for action listener of the button "run" looks like this:

    String model, data, output, solution, bounds ;
    double sol; 
    
    GlpkSolver solver = new GlpkSolver();
    GlpkSolver newprob = new GlpkSolver();
   
    
     
            
        model = "singleperiod.mod";
        data = "datasingle.dat";
        output = "outputsingle.txt";
        solution = "solutionsingle.sol";
        bounds = "boundssingle.txt";
        
        
        newprob = solver.readModel(model,data,output);
        newprob.simplex();
    
        sol = newprob.getObjVal(); 
        newprob.printSensBnds(bounds);
        newprob.printSol(solution);
           
If someone knows Java can you please help me??

Thanks