What HW version is your router?
What FW version is currently loaded?
What broswer are you using? Try a different browser like Opera or FF.
Mornig sunshine !
DIR-825 H/W: B1 F/W: 2.05EU (i've tested also with 2.03EU / 2.04EU)
Browsers used: IE 8.0 / 9.0, FF 7.0.1, Opera 11.52.1100, Chrome 15.0.874.5, Maxthon 3.1.7.1000, Safari 5.1.1
Don't hesitate to let me know if you need something else, i don't know, i'm new in this ... maybe cable lenght aprox. 8m, connection type RJ-45 T568-B Gigabit / 802.11n, position on the wall - vertical with antennas down ... so if there is everything else that you need to know and will help to change the routine that calls for /index.asp instead of /st_device.asp after login, of course as stated before, when WAN connecion is present/active.