Could be that the network is busy. If you're trying to download during a time when everyone else is as well you should be prepared for a lot of disconnecting. Still, I dont think there has been a major update since before ToAU was released.

When I used to play on my pc, I found if I kept dcing, sometimes if I cleared all my temporary internet files, cookies, history etc and reset my modem by turning it off for five minutes my connection would improve.

The other thing to check is that you dont have any Instant Messaging software running. Oh msn, why cant you and playonline just get along?