By “broke it up into four parts”, what do you mean? Are you just saying that the entire album doesn’t appear together in Album View or Cover Flow? Or something else?
If so, my guess is that there’s some tag that differs slightly between the sets of files. Try the following: select the first one of the songs, and “Get Info” (under the file menu.) Go to the “Info” tab, and use the “Next” and “Previous” buttons to cycle through the songs. If anything changes from song to song, then modify that tag so that it’s the same for all songs. The easiest way to do this is to select all of the songs and “Get Info” on them; a window will pop up allowing you to change the tags of all selected files at once.
If you tell iTunes to “Consolidate Library”, it’ll take all the music files that it knows about and move them into a file structure of its own; the top-level directories will be artists, containing separate sub-directories for each album. This probably won’t have too much of an effect on your problem.
This happens to me ALL the time. I agree with what MikeS wrote except that I usually check off all of the fields under Get Info that I don’t need to have anything in. Sometimes it’s just a matter of a few songs having comments, or the songwriter field being slightly different, I just overwrite them all with a blank entry.
The “consolidate library” command copies the music from it’s current location on your computer to the itunes music folder. Won’t help with this problem.