I spent a big chunk of the weekend ripping CDs to iTunes and rounding up cover art to go with them. By the time I was finished, I had almost 20 GB in my iTunes folder, which is about 2/3 of the capacity on the new iPod. I also made a few tweaks to the sort order on some of my older CDs, which were listed as "Various Artists" because the album's artist was performing a duet with another artist. To get around that, you just select all of the tracks and then put the album's main artist in the Album Artist sort field. Then I imported all of the new stuff and changes to the iPod, and took it to work with me last night.
When I turned it on, I was nonplussed to find out that an iPod that had worked perfectly with 13 GB on it suddenly would not work properly with 20 GB on it. It took forever to show the album listing, and then it would play about one song and then crash back to the main menu. I quickly figured out that the problem was in the new data that had been added. Either it didn't like having new information added in multi-gigabyte chunks, or it didn't like the album sort changes, or both.
I brought it home this morning and took all of the data off, then re-imported all of the songs from iTunes. When you're talking about some 5400 songs, that's a lengthy process. The good news is that after I did that, it appears to be working perfectly again.