My linksys router keeps locking my connection after I download too much. :|

Should I return it? I've already done the following things:

1) Called my ISP to ask if there's a stable connection going to my house

2) Upgraded the firmware on the router.

The thing is, I talked to people with the same router and they can download a lot, but they need to restart the router every few days. I was thinking maybe that's how all linksys routers are. The linksys router is wired, and has the option of wireless connections.

Any suggestions would be greatly appreciated!
- JB