Is anyone else having problems with a changing IP address?

I'm also having problems related to verification with my bank and with Hulu Plus. I ended up canceling Hulu because neither Hulu nor T-mobile had a solution.  Now it's my bank. So I went to a T-Mobile store to see if there's anything new regarding this issue with T-Mobile dynamic IPs. Apparently not, but a guy there suggested taking my T-Mobile gateway router/modem and plugging in another router to the gateway. He said this will give me a static IP address.  Is there anyone savvy enough to have an opinion about doing this?