OnTimer() weird behaviour

[Route206]

i have the following simple code for an OnTimer() function:
 

  void OnTimer()
  {
   int bla=FileOpen("last.txt",FILE_READ|FILE_CSV," ");
   if(bla==INVALID_HANDLE)
     {
      Alert("Problem reading file");
     }
   else
     {
      Alert("last.txt?, Got it!   ",TimeToString(time_stamp)," and  ",TimeToString(FileGetInteger(bla,FILE_MODIFY_DATE)));
     }
   FileClose(bla);
  }

Timer said is set for 30s and every 30s i get 2 Alerts with said text above

2 !!! how weird is that?? Sometimes they are 2s apart, but mostly they have exactly the same time-stap (not to be confused with time_stamp in code)

any ideas? i'm baffled... 

[Route206]

Never mind - i solved it.
And yes... it was a stupid mistake.