This seems to be happening most often when the artists have a guest performer and each new artist combination shows up as a new album. For example The Evolution of Robin Thicke - 13 tracks are him on his own - they are lumped together, then there are 2 tracks where it's Robin Thicke featuring Lil Wayne then there is 1 track featuring Faith Evans and another one featuring Pharrel Williams so all in all when I search for Evolution under albums it returns 4 albums!
I have uninstalled itunes and reinstalled it but this fragmentation issue was not resolved. Please help! I daren't synchronise my ipod at the moment for fear that this issue will manifest itself on there too!