If you own the cd you can rip the tracks again but join them this time.

Apple's Site on importing

The site doesn't tell you how to do it but it's easy. After inserting the CD go to the track listings and select both the songs (Left click the first song and shift+left click the second) then in the menu bar click on "Advanced" and "Join Tracks". Next Import the CD and "Replace Existing" tracks. The combined songs will not have a playcount or a rating since it is a "new" song. But atleast they will always play together.

If you don't own the cd, you could always burn the songs onto a cd.. cheers

Sometimes the Join Tracks selection is grayed out - not sure why - any ideas?

I had the same problem. I could not fins a way to get iTunes to join tracks. There was some obscure note in Apple's help that said the tracks needed to be sorted by track number.

I normally sort tracks by artist, so I click on the track number column and voila, Join Tracks was no longer grayed out and worked fine.