On one of my Mac’s, I had a problem with iTunes 8 where the songs from one album showed as split up as though they were on different albums in Grid View. Here is a screen shot (source).
To fix this problem, perform the following steps:
1. Highlight all of the tracks on the album.
2. Right-click on one of them and select Get Info.
3. Type a space at the end of the Album Artist. Click OK when done.
4. Right-click on the tracks again and go back to Get Info.
5. Take the space out at the end and click OK.
This totally works! It somehow resets iTunes into knowing all of the tracks are on the same album.