Q: Does iTunes Match ignore duplicates?

I have been loading vinyls onto iTunes using EZ Vinyl Tape converter. I have sync'd OK until recently when problems encountered with EZ. However there are some tunes on laptop to sync. After using the iPod touch as a camera I now cannot sync.  The laptop thinks the iPod is a camera and does not initiate iTunes, instead the laptop gets a totally blank screen and I cannot do anything, not even switch it off. I have scanned laptop for bugs, viruses etc using norton. I am totally stuck now.