Originally Posted by techflyer
It is hard to say without seeing code that can compile and show the problem. We can only guess if/when/how many times the methods are being called and what the value(s) of parameters are. Post a SSCCE
or be (much) more descriptive about what leads up to the problem.
Print out the full length of the array lists and verify they hold what you think they hold, every step of the way if necessary.
Post the revised version of the code any time you make a change and still have a question. Include the full text of any error messages.