Podcasts go into the wrong group when dragged onto my iPhone

Can anyone out there please help me with the problem I have when trying to update some Podcasts on my iPhone 4S (running iOS 7.00).

Although the selected Podcasts are all grouped under the same Name in my iTunes on my iMac, when I drag them onto my iPhone, they all get put into another group, which contain Podcasts that have nothing whatsoever to do with the ones that I have just moved!

What am I doing wrong?