OK, so I did some revising... and here's what I found out:
#1. The original script, not the snippet and also found in the footer, was missing </script> at the end of it. I find this very strange as I never edited it after it worked with version 1.2. The only thing I can think is that somewhere along the lines of upgrading from 1.2 to 1.5 the file was subsequently edited and then opened with the file being modified due to the new upgrade, which is even harder to fathom.
#2. Including either of the jQuery snippets that were provided by Wayanjaya or Frank did the trick when applied in appropriate sections.
#3. Including either of the jQuery snippets underneath the main, original script cancels out their function.
If I could, I'd give you hugs for your insightful input @(Frank, Wayanjaya, and Scott)! Thank you all very much for your support!