strange kppp behavior. No internet acceess after 1st dialup

[jodaka]

i'm a happy dialup owner so i'm using kppp to dial to ISP.
Few days ago strange things begin's for me.
When I start computer, logon and try to dial to ISP first time, after kppp connected (kppp minimize itself and show time online) I don't have any acceess to internet. For example ping google.com gives me "host unknown" or something similar.
OK. Then i disconnect, and connect again... and after second dial attemp everythnig ok and I can use internet.
Number that kppp is dialing is always same.

so what can it be?