Dissconected because of "mangled" data?

Since the 1.3.1 update (this problem didnt show up in 1.3) every time i connect its a guessing game as to how long it will be before i get disconnected because of this stupid message that makes little sence.

"You have been logged out of Second Life:

The viewer has detected mangled network data indicative of a bad upstream network connection or an incomplete local installation of Second Life. You might consider reinstalling to see if this resolves the issue."

The message goes on to say if it continues to contact SL support. I have reinstalled SL several times and i keep getting this message. sometimes when i am logging in the message comes up before the inventory has even finished dloading. What the heck is wrong?

Networking info:
MSN ADLS at 256/640kbps
Linksys Wireless Router BEFW11S4 v2
i am connected to a linksys (EZXS55W) 5 port switch wich is connected to my linksys router.
there are 3 computers on my network conneted to the router wirelessly and 4 computers (including the one i run SL on) connected to the router via ethernet cable.

I'm seeing this problem as well.... I've sent in a bug report, and yet to get a response. 1.3 is very, very bad for me and leads to me lagging out at least once a night. Never had this problem before in the past year.

-Bone