Interesting story about ENTERPRISE. When the show aired on UPN, it was already in the era of end-credit squeezing, so the promo for next week would run in half of the picture while the credits were scrunched into the other half of the screen. As a result, I never knew there was and end-credit theme tune for ENTERPRISE. It wasn't until just about a year or so ago when we opted to watch the show on Netflix that I finally heard that ending theme.
Normally, for a new STAR TREK series, I'd have run out and bought a soundtrack album whenever it was released, but I never did for ENTERPRISE. The theory of Trek-fatigue was surely in force there, as I felt it was more of a job each week to get the VHS recorder to grab a copy of ENTERPRISE's latest episode, and it felt like a vacation whenever a rerun was scheduled.
Harry
Some "Enterprising" Audio Video types have actually layered Enterprises End Theme (I believe it's called "Archer's Theme"?) over the opening title sequence and discovered that it matches up beat fro beat change for change. The general assumption is that the instrumental piece was originally intended as Enterprises opening theme. But for whatever reason someone at the executive level wanted something more upbeat and vocal. So they dusted off and reused that godawful song from "Patch Adams".