I'm not 100% sure this is caused by Newsbin, but here goes....
I run Newsbin 6.80RC7 Built 5054. On W7 with all updates installed. I have a paid account with Eweka.
The problem I'm experiencing is that Newsbin its download speed drops to 500KByte/sec or less.
Restarting Newsbin does not give me back my normal download speed (5MByte/sec)
Restarting W7 does give me my normal download speed.
Newsbin starts giving low download speeds after an unknown time (1 day?)
When Newsbin shows these low download speeds, then Chrome/eMule/uTorrent are able to download with normal speed (5MByte/sec)
I'm sorry that at this moment I do not have more information, but maybe other people recognize this issue?