Weird. It probably won't do anything, but have you tried booting into Safe Mode and rebuilding the database or setting a manual DNS address like Google's (8.8.8.8) instead of your ISP one?Around 70-80GB left.
You could also try using the webstore to remote queue the downloads. That should place them in your background downloads the next time you boot up the system and idle in the XMB or during check in for PS+ Automatic Updates.