Well, the removal of the port was actually the issue - not the solution. If I'd thought it was a solution, I never would've posted in the first place because I knew right away that with no port number my images resolved. But I wanted to know why.

And the only reason I even thought to try removing the port and see what happened was because my coworker sent me a screen shot of the app running locally on her PC, and I noticed the difference in our URL's.

If this thread is too confusing and is going to steer someone astray, by all means delete it.