In the future, when something "suddenly stops working" and "I haven't changed anything", look to see if you actually have changed something (like the processing environment).

That is certainly good advice and indeed, in my original post I stated that my first thought was, "well, it must be a result of something I did elsewhere...". In my defense, however, I was not aware that, of the two builds of Perl I had available, one was a 32-bit build and one was a 64-bit build. As well, I had been debugging my application for several hours beforehand with no issues from my scripts. I don't know how my paths suddenly got changed in the middle of a debugging session. I'm still rather bewildered about that. :)