IE10 shows no problems. RSS-source shows proper link /link pairs (as far I can tell).
So, blame RSSfeedscanner, probably it isn't capable of dealing with 100 titles at once (40+ KB of data).
Eg. when only reading 32 KB, then it could/would read a 'link' without the matching '/link'.
Try it yourself by opening the feed with safari (or whatever BROWSER you use).
For the record, uTorrent is able to deal with 7000+ titles, barely, without plugin

I've added the Nyaa-feed to uTorrent 2.2.1 and download of 100 torrents were started without any hickup

Because Vuze relies on Java, it could be a Java matter, like running out of bufferspace (memory).