I read something about a problem with Kazaa and IOS release 12.2 (13). What is the IOS release that you are using on your Router.You could also take a look at the release notes. Here's what it says.
NBAR is incorrectly matching packets as Kazaa2 in 12.2(13)T1. The problem was seen on a 7200-series router and 1700-series router and appears to be a platform-independent problem. Kazaa2 can use any available port, including DNS (53) and HTTP (80), and NBAR looks into the packet to see if it's a Kazaa2 packet.
This problem results in non-Kazaa2 traffic being matched and having actions taken on the traffic that are detrimental to network performance, such as the rate-limiting of DNS, web traffic, and e-mail (and only Kazaa2 traffic was configured to be rate-limited / policed). It can also cause other features to fail, such as vpn tunnels not coming up, because the packets needed to establish the connections are incorrectly marked as Kazaa2 traffic and possibly dropped or rate-limited.
The solution is to load the Kazaa2 pdlm currently available on CCO and use the "ip nbar pdlm" command to load the pdlm from flash.
Hope this helps.
