Scrubber bar displays only fraction of total time

So, I recently decided to add some Ricky Gervais radio recordings to my iPhone's library as podcasts. I downloaded these around 4-5 years ago and at the time used my zune (I know, I know -.-) to play them. So I after I sync them to my iPhone and try to play them, I notice that the scrubbing bar on top is displaying a ridiculously short total time for the podcast. I sort of shrugged it off because I was at work and couldn't do much about it at the time. Now mind you, these recordings last anywhere from 40 minutes to an hour. The time displayed ranges from 2-4 minutes. This wouldn't really be an issue, but it does not allow me to pause or rewind after it reaches the shorter time displayed. The podcast will continue playing if left alone, but once you hit pause or try to fast forward or rewind it will revert back to the end of the 2-4 minutes. This gets to be a pain because then I have to fast forward through the use of the playback speed button in order to reach the place I was at. These files are all .mp3s. I did add them manually to my iTunes library and then change their media type to podcast. The podcasts display regular time when playing on my desktop's iTunes. I recently noticed that the correct time displays for a fraction of a second when I begin to play one, but then switches itself to the shorter time (using the scrubbing bar during the time that it flashes the correct time does nothing as it just starts playing at the end of the shorter time displayed). I'm pretty sure this problem is something I have done on my end, but I'm not sure what that might be. I'm willing to try anything out just to fix this issue.