Speedtouch 510 problem

[Deezire]

Hi all...

i`ve got a problem with my speedtouch 510 router..

after XP has booted up..

it will show the router for about 1 minute..

and than it just disappears..

and after 10 or 20 minutes it will come back..

but than it wil disappear again in 1 minute..

i also cannot access my router webpage (10.0.0.138)

I already removed the firewall, with no effect..

and i tried 3 different firmware`s all with the same problem..

(4.2.3.0, 4.2.5.0, 4.2.7.16)

has someone experienced the same problem or does someone

know a solution to this problem???

(sorry for my bad english)