Manual Update = Lost Videos

Hi everyone, perhaps someone out there can help me. I have a 5G iPod with video that I automatically sync to iTunes on my home computer 99.9% of the time. The other .1% of the time, I am on the road and want to use my laptop to transfer podcasts to my iPod. I read the "Using iPod with Multiple Computers" article. When I connect to the laptop, I say "no" to linking to the laptop library, switch the iPod to manual mode and drag the podcasts over to the iPod. However, when I do this, my videos are deleted from the iPod. I also noticed that my automatic settings for photos and videos were changed when I went back home and synced to my home computer. Is there a way to keep all of my home desktop settings automatic, not loose any data from my iPod, but still manually update podcasts from my laptop when traveling? Thanks for the help.

iMac, iBook Mac OS X (10.4.6)