OK, no problem, but why don't you, on the other hand, just trust Don Cragun that he knows what he talks about? If you just provide him with the necessary information he might just find out (and then explain it to you), but instead:

you just said something amounting to "no, that can't be". First: about the truthfulness or quality of the information: you just might have ommitted some vital point because you didn't recognise it as being vital. I do not say this is the case but it might be. And even if this is the case: you are a beginner - you are supposed to not get it right every time. There are no bad feelings, it is just about finding out the culprit.

Now, the second point: maybe the perl script you have has a problem, maybe not. If it does it would be simple enough to test: rename one of the files to "0" (as the name Dons script used) and try it manually. If you get the same result Dons suspicion about the perl script being the problem is proven and there is no shame in saying so. You might still decide then to use the workaround you used now, but you would learned something about the script. Maybe you get a correct result and that would prove Dons suspicion wrong. In this case just write here "i have tried that with the command XXXX and got the correct result of YYYYY and therefore your reasoning is wrong. This in turn helps us finding out what indeed the problem is and might lead to some (other) solution. This is how an expert would have handled that.

Either way, this is the way we (not only we in this forum, but UNIX admins everywhere) work: we have an unexplainable problem, we create theories of what is going on, then create testbeds to prove/disprove these theories until we finally find a solution. And more than amassing factual knowledge will getting into this mindset help you advancing from beginner to seasoned to expert.

I hope this helps.

bakunin