Have a look in the LW beta section of the forum. There's a post that might be related. Apparently there's an update coming out on Monday. I've never heard of LW doing anything like that before. DO you have a decent anti-virus program with updated definitions? Do you have spyware, etc. Check these out:

ad-ware http://www.lavasoftusa.com/software/adaware/ (FREE)

Spybot - Search & Destroy http://www.safer-networking.org/en/mirrors/index.html (FREE)

Peerguardian: http://peerguardian.methlabs.org/pg2.html (FREE)