The Value error has to do whit a corrupt DB file, as download size is a negative value. "-1460"
Try delete the cache file in install dir.
You must have connection as the info window is ok and the DB was downloaded (even if it seams to be corrupt) so i don't think it's the firewall.
Does all files timeout ??
The downloader has a timout of 15 sec, is this to low for your connection ??
The "in use" error is harder

some time it helps to restart the computer.