iTunes not syncing correctly

Hello All

Like many others, iTunes is not syncing all my songs to my iPhone, but instead only copies around 300 and then stops, the rest seemingly copied and the mini bar chart at the bottom of the sync window showing all the songs copied. However when playing them on the phone I get red circles with little squares inside, and when I view the iPhone's contents through iTunes, the non-copied songs are grey with dotted circle icons.

I do not have iTunes Purchases in the cloud visible on the device.

I have tried many of the methods people use to fix this from other threads, but none have worked so I have resorted to starting a new thread.

I have tried completely erasing and restoring the iPhone

I have tried completely rebuilding the iTunes Library as per this method.

I have tried manually syncing, and it worked for the first 300 songs, but then stopped copying them.

I have tried only syncing by specific genre/playlist/artist etc, no dice.

I have an iPhone 4s 64gb with iOS 7.1 and a 27-inch 2009 iMac with OS 10.9.2 and iTunes 11.1.5 (5) 64-bit.

The annoying thing is, everything syncs fine with my iPad Mini Retina....

Please help, this is really getting on my nerves.

Thanks,

xeni