IPhoto not appearing in Itunes - cannot sync to ipod - try this

I had this problem for a while. When ever I went to try and sync my photos from iphoto onto my appletv/ipod, I would get the error message:

An unknown error occurred [-50]

Before I continue, I should point out, that I had moved my itunes library to an external hard disk, but if you are getting this error, might be worth giving this ago.

I had tried several things before to try and get it to sync, such as
Rebuilding the Library
Deleting the Cache
Checking for photos with keywords with ampersands, and removing them.

I then came across this post on macrumours, which talks about the AlbumData.xml file - something I hadn't looked at before. Opening it up, I could not find any error messages or corruption, as other people have mentioned, but I did notice this; In the part which contains information about slideshows, I noticed the filepaths were pointing back to where my itunes library used to be. I opened up iphoto, deleted these slideshows and hey presto! Can now once again sync