iCloud errors after itunes update

I've just downloaded the latest all new itunes and a load of my songs that used to work fine in the cloud now i have the exclamation mark in the cloud icon. When i right click,i get "this item was not added to iCloud because an error ocurred" I've tried converting to MP3 and get "an error ocurred while converting the file.The file format is not valid." These tracks are apple lossless.

I also have the cloud icon with a diagonal line through it. "This item is not eligible for icloud" Fair enough....but i'm sure they were ok before the update. (various file formats,mostly music videos)

I've got 18 tracks "waiting"

about 100 apparently invalid (fine before latest itunes)

72 in the cloud (woohoo!)

and about 9000 with no cloud icon at all!

I've clicked on Match,and it's now up to date.... hmmm.

This *****!