Hi there,
I have this issue with a brand new router.
When I want to enter admin web-interface, I log in with my personally changed password, then I see home page of the router interface just for a second or fewer, and finally I get dropped back to login page.
Sometimes I enter and work with the router settings succesfully (but it happens in 1% times).
Firmware is 3.0.0 R1.
Please help )