First of all, did you follow gellyfish's suggestion and compare the versions of the File::Find module itself? Did they report version differences?

Secondly, while you included code to show how it is deciding to do something with the desired files, you showed nothing regarding what you are doing with the match. Are you storing something related to the match in an array, hash, object, or other "growable" data structure of some kind?

My only other concern would be in that you are creating what is essentially a daemon process that runs continuously, with short (3s) pauses between processing. Not knowing your particular application, I cannot say this is or is not the best way to approach it, but if it is not essential to the application, you might consider limiting the number of times the app runs, in combination with the system's cron (or similar) feature, to keep the app from running too long if it does indeed have some form of memory leak.

Not sure that helps, but hope it at least gives you something to look at.