Problem syncing iPhone with music on iTunes

[SurreyGuy]

I have an iPhone 4 and have never had any problems syncing it..........till now!

I have my PC set to automatically sync my music when the iPhone is connected.

It is currently syncing every track that is "ticked", except 5 x tracks by the same band and from the same album (dunno if that is significant).

When I then manually add those 5 x tracks to my iPhone, only three of them appear in the "Songs" listed on my phone. The album from which they are taken appears twice on my iPhone - when you "go into" the first one shown, you can see all 5 x songs, but when you look in the second album that shows, you can only see 3 of the songs!

I've followed the troubleshooting process in the "iPhone help" section on iTunes, but the problem still exists!

Please help.