Update on Yesterday's Problem
Ok...so leave it to Microsoft IIS to be the cause of my problems yesterday. In case anyone runs into this issue, I did do some reading up on session_id() as suggested by 
zenmondo along with testing the broken session bug that I had read about in a forum. Here's what ended up...
Yes, Microsoft IIS has a bug with session variables. For some reason, there are instances when it doesn't recognize a session at session_start() and assumes it needs to start a new session. So, on the page I have that checks authentication, I had it grab the session id after it was started and passed it through the URL. Then, I had it pull in with a $_GET and set the session id on the next page using that. From there on out, the sessions work fine. Go figure. Seems like an odd work around, but it works.
zenmondo along with testing the broken session bug that I had read about in a forum. Here's what ended up...Yes, Microsoft IIS has a bug with session variables. For some reason, there are instances when it doesn't recognize a session at session_start() and assumes it needs to start a new session. So, on the page I have that checks authentication, I had it grab the session id after it was started and passed it through the URL. Then, I had it pull in with a $_GET and set the session id on the next page using that. From there on out, the sessions work fine. Go figure. Seems like an odd work around, but it works.