Sometimes when you go to play a podcast the iPad will start playing a different podcast than the one you wanted to hear. This happens because the file doesn't have an album name in the metadata.
To fix the problem you have to edit the podcast in iTunes on your computer.
1. Make sure the podcast is on your computer in iTunes (you might have to download the podcast or sync it from the iPad)
2. Select the podcast in iTunes. On the top menu bar click File -> Get Info
3. Click the Info tab. Enter a title in the Album field
4. Click OK and sync the edited podcast to your iPad. The file should play normally.