Please I need help !

I setup my modem (USR5610b performance pro) in Mandriva LE 2005 on ttyS4 (com5) and it works great with minicom and wvdial. I can get a ppp connection at 49333bps. But I have two problems I did not find solutions yet.

1- KPPP : I deleted my modem setup and I created a new one but this new setup does not have the modem commands in the tab modem=>edit=>modem commands. When I try to connect, it crashes. It does not initialize. I tried to reintall KPPP but Mandriva forbids me to do it since it is already installed.

2- Even with a ppp connection (through wvdial or KPPP), I cannot use my web browsers. I tried to ping IP addresses but it did not work.

Do you have any clue on how to solve these problems ?

Thank you very much