Databases and button Back incompatible ??

Hi,

I have my database which has currently 3 tables. I open the DB from screen1 (which is a list of items) and can navigate to screen2a (which reads records from the DB). If any record is found according to search condition entered by user, screen2a displays an overview for the user to select the option and then we navigate to screen2b. So far so good.

If from screen2b I press button Back, it takes me to screen2a but then I cannot search for another record because the following instruction is not executed:

  DEMODB.transaction(
      function (transaction) {
        transaction.executeSql(myQuery, null,
            dataSelectHandler2, 
            errorHandler);
      }
  );

It was successfully executed the first time. Debugger does not trigger an error message, it´s just that DEMODB.transaction is not executed a second time and therefore, neither dataSelectHandler2 nor errorHandler are executed. I changed then the code behind Back; instead of GoBack I declared GoToScreen and this time it works. So somehow the application is lost with GoBack; it seems that it does not know where it is.

Now if I navigate from screen1 to screen2a I can execute any number of times the query and display the information. If I go back to screen1 and navigate to screen3 or screen4 and then to screen2a via Screen1, it does not work anymore. As I mentioned, the above code is not executed and I cannot understand why. There´s no error neither at runtime nor at design.

When the above occurs, I try to verify if my DB is open and if the information is available. The system goes mad, the icon with the DB is not expanded totally (see screenshot) and it crashes. MobiOne is closed after a short dump.

What is the reason for this ??