Does iphone 'manually manage' only work on one computer? I have 'manually manage' enabled on one computer but when I plug it into another computer, manually manage is unchecked and I can't manually manage. If I do, it wants to wipe the media content first. If this is by design, it is lame.
Ah here it is... Of course it's by design. The article in the link will take you through a way to sync the iPhone with one computer and manually manage the iPhone on a second computer. Worked for me, had issue when I did it for my wife... so expect some headache.
Here is a work-around. While you iPhone is connected to the second computer (not your main computer), use "copy" and "paste" to get your music or podcast from the iTunes library of your second computer to your iPhone.
Highlight the song or podcast in the iTunes library and "copy", and then click on the "music" or "podcast" section (as applicable) under the device in the iTunes window and "paste". The second computer has to be "authorized" for this to work,meaning it becomes one of the 5 computers you authorize to use your iTunes account.