Hey, thanks for the responses to my earlier post
After tooling around with the settings, and checking online, I found a solution from a post on Amazon for my dvd player. Basically, if I set my dvd player to output at 480p instead of 720p or 1080i, the LC2600N can change the aspect ratio again. I'll quote the helpful part of the guy's quote here just in case anyone else is having trouble along the same lines as I did.
"When using the HDMI digital interface, I have found 480p to be the best selection. Anything other than 480p causes distortion of the picture for a disc with non-widescreen content. Selecting 480p turns off the DVD players upscaling feature and allows my HDTV scalers to format the picture correctly for my display. Also, selecting 480p restores functionality to the "format" button on my HDTV remote control, thus allowing me to select a format that produces the best picture." (credit goes to Will on Amazon.)
Since I'd rather have a correctly formatted picture than one playing at 720p or 1080i, this solution worked out pretty well for me.
Hope that helps anyone having similar problems with their dvd player and thanks again for those that gave advice and welcomed me to the forum!